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We have developed a new and compact β-nuclear magnetic resonance (NMR) system using beta-radioactive nuclei. By using a Halbach array permanent magnet to create a static magnetic field, and a scintillating fiber as a detector, we succeeded in significantly reducing the size and weight of the entire system. The performance of the new spectrometer was tested and evaluated by observing an NMR spectrum of 19O (T1/2 = 26.9 s, I = 5/2) in TiO2. [ABSTRACT FROM AUTHOR]

The Heusler type compounds (A2-x-yZy)MnZ (A = Ni, Pd, Pt; Z = Sb, Sn; x = 1, 0; and y = 0, antisite defects of Z atoms) are investigated to understand the induced magnetic properties. The structural phases C1b type half Heusler (x = 1, y = 0) compounds AMnZ and the corresponding L21 type full Heusler (x = y = 0) compounds A2MnZ and some disordered compounds (A1-yZy)MnZ and (A2-yZy)MnZ (y = 0.01, 0.05) were calculated using the Korringa-Kohn-Rostoker Green's function method. The antisite doping of 1% (5%) Sb retained (suppressed) the half metallicity at (Ni1-ySby)MnSb, whereas the other compounds were found to be gapless in both spin directions. The density of states at the Fermi level exhibits the explicit spin polarization in the compounds. The net magnetic moments of the compounds are closer in their values, wherein the manganese atom is responsible for the major contribution to the magnetic moments, which is much larger than the partial moment of the other constituents. The Curie temperature (TC) of the ordered ferromagnetic compounds was estimated using the mean-field approximation. The TC higher than the room temperature was found for the ordered compounds, except for the cases of Pt2MnSb and Pt2MnSn. No literature value of TC has been reported yet for these two compounds. Calculated spin moments and TC agree well with the experimental results, where available. [ABSTRACT FROM AUTHOR]

Owing to attractive properties of 2D transition metal dichalcogenides (TMDCs), MX2 has obtained much attention. Therefore, using first principles calculations, investigations have been carried out on structural, half, and full metallic behavior and their impact on magnetic properties of transition metals (TMs), such as Cr, Mn, Co, Ni, and Cu, doped MoS2. Two supercells (3 × 3 × 1 and 2 × 2 × 1) were designed and the same element was doped in both supercells to observe the effect of dopant on electronic, structural, and magnetic behavior of the host material. After the Cr, Mn, and Ni doping, a slight band gap was observed as compared to the pure material. However, Co shows the half metallic behavior in 3 × 3 × 1 supercell but it shows the metallic behavior after doping in 2 × 2 × 1 supercell. On the other hand, the doping of Cu determined the metallic behavior in both the selected supercells. Electronic behavior in terms of total density of states (TDOS) and partial density of states (PDOS) and how orbitals are participating in band formation are discussed in detail. From TDOS and band diagrams, it was found that, except Cr, all other doped elements induce magnetic moments in nonmagnetic MoS2. Our calculated results would give the detailed information on magnetic behavior of TMs doped MoS2 and their impact for application in efficient electronic and spintronic devices. [ABSTRACT FROM AUTHOR]

First-principles calculations accomplished to investigate structural, mechanical, thermal and magnetic properties of newly designed CoNbCrZ (Z = Al, Ga, Si, Ge) Heusler alloys (HAs). Generalized gradient approximation (GGA) and Hubbard potential (GGA + U) are used as exchange correlation functional. Geometry optimization calculations show that all these HAs are stable in Type I structure. Further calculations are carried out for non-magnetic (NM) and magnetic phases and found that all considered alloys are stable in ferromagnetic (FM) phase. GGA and GGA + U approximations executed to obtain electronic structures of CoNbCrZ (Z = Al, Ga) HAs, while GGA approximations performed for CoNbCrZ (Z = Si, Ge) HAs. Magnetic properties revealed that following alloys i.e. CoNbCrAl and CoNbCrGa are complete half-metals (HM) while CoNbCrSi and CoNbCrGe are NM semi-metals in nature. All these alloys are obeying Slater-Pauling rule (Mt = 24-Zt) and calculated magnetic moments are in well agreement. Mechanical parameters show that all alloys are stable and ductile in nature as well as have anisotropic behavior. High Debye temperature and melting temperature also authenticate the thermal stability of these alloys. Furthermore, negative formation (Ef) energy indicated that all these alloys could be synthesized experimentally. [ABSTRACT FROM AUTHOR]

We proposed a data-driven science study by Bayesian spectroscopy to analyze an X-ray magnetic circular dichroism (XMCD) spectrum and magnetic moments. In Bayesian spectroscopy, model selection becomes available to estimate the number of spectral components by using Bayes free energy. To demonstrate such advantage, we decomposed synthesized X-ray absorption (XA) and XMCD spectra at the L 3 , 2 -absorption edge of the Ni ion in NiFe 2 O 4 . In the synthesized ∓ helicity XA spectra, random noise was superimposed and a finite spectral width was convolved to mimic measured spectra. From these XA spectra, spectral components having intensity beyond the noise level were successfully extracted without excess or deficiency although transition components in close proximity within the spectral width were merged. From the XMCD spectrum, we also succeeded in extracting separately the original ∓ helicity components although an additional − helicity component comparing with the case of XA spectra was extracted in the model selection. This additional component was extracted to explain an asymmetric XMCD spectral structure at the L 3 edge, and this result demonstrates that Bayesian spectroscopy can fully exploit the advantage of XMCD measurements being superior for detecting close transition components of opposite helicities. In addition, we proposed to use posterior probability distributions obtained by Bayesian spectroscopy for estimating magnetic moments through samplings of the spectral intensities for the separately decomposed ∓ helicity components on the L 3 , 2 -absorption edge. [ABSTRACT FROM AUTHOR]

Heusler alloys are theoretically predicted to become half-metals at room temperature (RT). The advantages of using these alloys are good lattice matching with major substrates, high Curie temperature above RT and intermetallic controllability for spin density of states at the Fermi energy level. The alloys are categorised into half- and full-Heusler alloys depending upon the crystalline structures, each being discussed both experimentally and theoretically. Fundamental properties of ferromagnetic Heusler alloys are described. Both structural and magnetic characterisations on an atomic scale are typically carried out in order to prove the half-metallicity at RT. Atomic ordering in the films is directly observed by X-ray diffraction and is also indirectly probed via the temperature dependence of electrical resistivity. Element specific magnetic moments and spin polarisation of the Heusler alloy films are directly measured using X-ray magnetic circular dichroism and Andreev reflection, respectively. By employing these ferromagnetic alloy films in a spintronic device, efficient spin injection into a non-magnetic material and large magnetoresistance are also discussed. Fundamental properties of antiferromagnetic Heusler alloys are then described. Both structural and magnetic characterisations on an atomic scale are shown. Atomic ordering in the Heusler alloy films is indirectly measured by the temperature dependence of electrical resistivity. Antiferromagnetic configurations are directly imaged by X-ray magnetic linear dichroism and polarised neutron reflection. The applications of the antiferromagnetic Heusler alloy films are also explained. The other nonmagnetic Heusler alloys are listed. A brief summary is provided at the end of this review. [ABSTRACT FROM AUTHOR]

The structural growth pattern of medium‐sized holmium‐doped silicon nanoclusters HoSin0/− (n = 10–18) was systematically probed by means of unbiased structure searches and double‐hybrid density functionals. The identified global minima of the nanoclusters have been confirmed by comparing the calculated spectral properties such as photoelectron spectroscopy, adiabatic electron affinities and vertical detachment energies with the experimental data. The structural evolution reveals Ho‐linked configuration for neutral and anionic nanoclusters (starting from n = 10 and 12, respectively). In this configuration, the linker Ho atom connects two small silicon sub‐clusters. The nanoclusters starting from n = 16 prefer the configuration in which Ho atoms reside in the center of Si‐cluster. The natural population analysis interprets the involvement of 4f electron of Ho atom in bonding. The participation in bonding has been traced by a transition of an electron from 4f to 5d orbital. This also results in larger magnetic moments (4 and 5 μB) than that of an isolated Ho atom. The HoSi16− nanocluster has good thermodynamic and moderate chemical stabilities as corroborated by average bond energy analysis, highest occupied molecular orbital‐lowest unoccupied molecular orbital gap, and chemical bonding, thus suggesting it the most appropriate building block for new functional nanomaterials. [ABSTRACT FROM AUTHOR]

Measurements of the magnetic moment of a ship are necessary for monitoring safety from magnetic mines and from stealth, by the magnetic field. A modification of the method of measuring the magnetic moment of a ship by using a three-component differential magnetometer is examined. With the aid of computer modeling, a comparison was done of the errors of the method developed by the authors with those of known analogs, and its advantage in precision (by practically one order of magnitude) was established. It is shown that the proposed method can be applied also to magnetic models of ships and standard samples of magnetic materials in order to determine the components of hysteresis loops by magnetization. [ABSTRACT FROM AUTHOR]

Transparent conducting oxides (TCOs) are semiconductors gaind much interest due to applications in optoelectronic and tranport properties. Herein, we investigated optoelectronic and tranport properties of Rh doped Fe3BO6 compound. The band structure of parent compound for spin up shows insulating nature while other channel is semiconducting nature (4.181 eV Up/2.41 eV Dn). When spinel material doped with Rh3+, the band gap is reduced for both spin channels (2.59 eV (Up)/ 0.59 (Dn), respectively. The optical dispersion exhibits strong absorption in the UV region, for both materials. Reflectivity spectra, for both materials visible-UV indicating good coating materials to reduce solar heating. The transport parameters are computed. It's observed that large ZT value Fe3BO6 made this compoud most promisining in thermoelectric applications. The effective masses of species were also analyzed by curve fitting method, results showed that nature of band at 0.69 is changed from direct to indirect for doped compound. [ABSTRACT FROM AUTHOR]

In this study, we theoretically probed the electronic, magnetic and optical characteristics of Sr1-xFexTiO3 and SrTi1-xFexO3 perovskite materials with the implementation of DFT based Wein2K code. In both doping atom is partially removed by (Fe) dopant. The substitution of Fe at A-site in SrTiO3 consequences the half-metallic ferromagnetic (FHM) character, while the substitution of Fe at B-site in SrTiO3 resulted into metallic character of the studied material. Moreover, In Sr0.5Fe0.5TiO3 the local magnetic moment of Fe is slightly decreased, whereas in SrTi0.5Fe0.5O3 the Fe magnetic moment is highly decreased from its free space value 4 µB. This reduction is due to p-d hybridization. In case of Sr0.5Fe0.5TiO3, the exchange constants N0α for s-d and N0β for p-d interaction are computed. The optical response of studied materials is described by jn.hat Sr0.5Fe0.5TiO3 is a prominent candidate for spintronics applications. [ABSTRACT FROM AUTHOR]

Density functional theory has been used to study the structural, elastic, electronic, magnetic and optical properties of Ti2FeSb Heusler alloy using generalised gradient approximation implemented through the WIEN2k code. The cubic structure of Ti2FeSb is mechanically stable in the F-43m space group and shows elastic anisotropic properties with ductile nature. Ti2FeSb shows spin gapless semiconductor behaviour along with an indirect energy band gap (EG) of 0.10 eV along the Г-Χ in majority spin (γ-spin) band above the Fermi energy level (EF) and 0.90 eV in the minority spin (δ-spin) band at EF. The total magnetic moment is 3 µB at optimized lattice constant (ao) 6.32 Å and follows the Slater–Pauling curve for inverse Heusler alloys. Robustness of this material with respect to change in the value of ao is evident in the constancy of magnetic moment along with retention of the half metallic nature within a lattice variation ±4% from equilibrium value of ao. Reflectivity, optical conductivity, dielectric function, absorption coefficient and energy loss have also been investigated as a function of incident energy for this alloy. [ABSTRACT FROM AUTHOR]

Herein, optoelectronic, elastic and magnetic properties of L21 structured Co2VZ (Z= Pb, Si, Sn) full Heusler compounds have been investigated by two methods. One is full potential linearized augmented plane wave (FP-LAPW) method as implemented in WIEN2k and second is pseudo potential method as implemented in Atomistic Tool Kit-Virtual NanoLab (ATK-VNL). All these compounds shows zero band gap in majority spin channel in the both simulation codes and a finite band gap are 0.33 and 0.54 eV in Co2VZ (Z= Pb, Sn) alloys (semiconducting) respectively. Due to minority-spin channel near the Fermi level as implemented in WIEN2k code and showing 100% spin polarization except Co2VSi (metallic) with zero band gap. These compounds found to be perfectly half-metallic ferromagnetic (HMF). However, above mentioned compounds shows finite band gaps in ATK-VNL code. The calculated magnetic moment of these compounds Co2VZ (Z= Pb, Si, Sn) are 3.00 and 3.00, 3.02 and 2.96, 3.00 and 3.00µB in WIEN2k and ATK-VNL codes respectively. Thus we have observed that the calculated vales by these simulation codes and Slater-Pauling rule have nice tuning. Optical properties of these compounds like as reflectivity, refractive index, excitation coefficient, absorption coefficient, optical conductivity and electron energy loss have been analyzed. Absorption coefficient and electron energy - loss function values are increases as we increase the value of energy. The vales of Pugh’s ratio B/G is greater than 1.75 for all compounds and showing ductile nature with positive value of Cauchy pressure (CP = C12 – C44) and shows metallic behavior of Co2VZ (Z= Pb, Si, Sn) compounds.

The article presents the results of quantum-mechanical computer simulation. The purpose of studying the electronic and magnetic properties of twenty crystalline structures based on perovskites of transition metals with the general formula ABO3 (where A - Ca, Ce, Y, Na; B - Ti, Ta, Nb, Mn, Fe ion; O - oxygen ion) is to assess the possibility of using this group of materials in modern electronic devices. Systematization of fundamental characteristics will allow further describing of the physical mechanisms that occur in structures. Calculations of the fundamental properties of crystals were performed using first-principle methods based on the density functional theory (Density Functional Theory - DFT). The VASP software package (Vienna Ab initio Simulation Package) was used as the simulation tool, which is designed to perform quantum-mechanical calculations. As a result of the simulation, the following characteristics of perovskites of transition metals were established: ABO3 unit cells have cubic syngony; a number of compounds have a magnetic moment (from 0.26 to 4.39 p®); an analysis of the band structures shows the presence of compounds with a semiconductor (band gap from 1.65 to 2.99 eV) and metallic type of conductivity. The direct-gap type of conductivity was established for only CeTiO3 compound. The results obtained quantitatively and qualitatively characterize the electronic and magnetic properties of crystalline structures based on ABO3 perovskites and can be used to develop methods for calculating the basic electrophysical parameters of promising electronic components.

In this paper, we have studied the structural, electronic, optical and magnetic properties of Co2CrZ (Z= Al, Bi, Ge, Si) compounds by using two different methods one is full potential linearized augmented plane wave (FP-LAPW) method as implemented in WIEN2k and second is pseudo potential method as implemented in Atomistic Tool Kit-Virtual NanoLab (ATK-VNL). The respective band gaps in their minority-spin of Co2CrZ (Z= Al, Bi, Ge, Si) are 0.696, 0.257, 0.602 and 0.858 eV near the Fermi level, which is implemented in WIEN2k code and showing 100% spin polarization. Further, these compounds have been found to be perfectly half-metallic ferromagnetic (HMF). However, above mentioned compounds shows zero band gaps in ATK-VNL code. The calculated magnetic moment of these compounds Co2CrZ (Z= Al, Bi, Ge, Si) are 3.06, 4.99, 3.99 and 3.99µB respectively in FP-LAPW method. However, the respective magnetic moment of these compounds is found to be 3.14, 5.08, 4.11 and 4.08µB in ATK-VNL code. Optical properties play an important role to understand the nature of material whether it can be used as optoelectronics device. From the optical Spectra, complex dielectric functions calculated values are 312.370 and 141.991, 299.812 and 111.368, 288.127 and 106.342, 290.688 and 99.095 for the compounds Co2CrZ (Z= Al, Bi, Ge, Si) respectively by using WIEN2k. The maximum energy loss is observed between 11.4 to 13eV for above these compounds. The refractive index values for the compounds Co2CrZ (Z= Al, Bi, Ge, Si) are observed as 18.104, 17.602, 17.252 and 17.289 respectively. In the optical conductivity spectrum a sharp peak is observed at 1.6 - 2.3eV.

A series of pentagonal bipyramidal anionic germanium clusters doped with heavy rare earth elements, REGe 6 - (RE = Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), have been identified at the PBE0/def2-TZVP level using density functional theory (DFT). Our findings reveal that the centrally doped pentagonal ring structure demonstrates enhanced stability and heightened aromaticity due to its uniform bonding characteristics and a larger charge transfer region. Through natural population analysis and spin density diagrams, we observed a monotonic decrease in the magnetic moment from Gd to Yb. This is attributed to the decreasing number of unpaired electrons in the 4f orbitals of the heavy rare earth atoms. Interestingly, the system doped with Er atoms showed lower stability and anti-aromaticity, likely due to the involvement of the 4f orbitals in bonding. Conversely, the systems doped with Gd and Tb atoms stood out for their high magnetism and stability, making them potential building blocks for rare earth-doped semiconductor materials., (© 2024 Wiley Periodicals LLC.)

In this study, nano-sized individual Tb2O3 particles synthesized by the laser ablation method were extensively characterized and assessed as suitable precursors for the fabrication of transparent magneto-optical ceramics without requiring the introduction of grain growth inhibitors and stabilizing additives. The as-produced powder comprised 13 nm particles with a spherical shape and monoclinic crystal structure, whose full transformation into cubic phase was achieved after heating at 950 °C and 700 °C under vacuum and Ar gas, respectively. After subjecting the nanopowder compact to pre-sintering at 1350 °C, the microstructural features were investigated along with their correlation to the optical transmittance of Tb2O3 ceramic hot isostatically pressed (HIPed) for 2 h at 1450 °C under 200 MPa. The as-HIPed sample had a brownish color, with an optical transmittance of 65.3% at a wavelength of 1060 nm and an average grain size of 14 μm. The Verdet constant measured at wavelengths of 633 nm and 1060 nm was 471 rad T−1 m−1 and 142 rad T−1 m−1 to confirm a very high content of magneto-active Tb3+ ions. The obtained results indicate that laser ablation synthesis of nanoparticles followed by pre-sintering and HIP is a promising approach for the manufacture of magneto-optical Tb2O3 ceramics without specific sintering aids.

The Faraday effect is used to measure the temperature dependence of the magnetic susceptibility in the temperature range from 300 to 1200 K of rare-earth chromium borates, such as NdCr3(BO3)4, SmCr3(BO3)4 and LuCr3(BO3)4. It is found that this temperature dependence follows the Curie–Weiss law in each phase. The obtained Curie and Neel temperatures as well as magnetic moments match the formula unit of borate crystals. [ABSTRACT FROM AUTHOR]

Within the framework of general relativity, possible effects of the gravitational interactions in the Dirac spinor field are considered. It is shown that these interactions manifest locally as contact spin-spin interaction of the gravitational and spinor fields. This interaction leads to the classical rotation of particles with spin ħ/2. As a result, this leads to the appearance of local internal space-time with specific geometric properties for each particle. New effect of an increase of the mass of spinor particles due to this interaction is found. Also, an explanation of existence of a magnetic moment in the Dirac spinor particles as a result of a local electro-spin-spin interaction has been proposed. [ABSTRACT FROM AUTHOR]

Using UB3LYP/6-31G*(d) density functional level of theory, the structural, electronic, optical and magnetic properties of B 24 N 24 , Li @ B 24 N 24 , Na @ B 24 N 24 and K @ B 24 N 24 cages were studied when M (Li, Na, K) atoms locate at center of B 24 N 24 cage. Results illustrate that the capsulation of M atom in B 24 N 24 cage increases the bond length of B–N. In addition, the stability of M @ B 24 N 24 cages corresponds to size of atomic radius of M atom. B 24 N 24 cage becomes magnetic by the capsulation of the M atom in B 24 N 24 cage. K @ B 24 N 24 and Na @ B 24 N 24 cages have a minimum (0.976 μ B ) and maximum (1.185 μ B ) values of total magnetic moment, respectively. Numerical results show that polarizabilities values of K @ B 24 N 24 and Na @ B 24 N 24 molecules are about 1.6 times bigger than that of B 24 N 24 molecule. [ABSTRACT FROM AUTHOR]

Composite nature of a particle can be probed by electromagnetic interactions and information about their structure is embedded in form factors. Most of the experimental and theoretical efforts on baryon electromagnetic form factors have been focused on nucleon while the data on charmed sector are limited to spectroscopy, and weak and strong decays. Forthcoming experiments with a heavy-hadron physics program at major experimental facilities are expected to provide a wealth of information on charmed baryons, which calls for a better understanding of the heavy-sector dynamics from theoretical grounds. We review the progress in calculating the elastic and transition form factors of charmed baryons in lattice QCD. A collection of static observables, e.g. charge radii, multipole moments, are presented along with the elastic form factors up to Q 2 ∼ 1. 5 GeV 2 . As one would expect the charmed baryons are compact in comparison to nucleon and this is due to the presence of valence charm quark(s). The elastic and transition magnetic moments are both suppressed. The lattice results provide predictions for the transition magnetic moments, transition and helicity amplitudes and consequentially the decay widths of some singly and doubly charmed baryons. In general, lattice results are consonant with the qualitative expectations of quark model and heavy-quark symmetry, although there are apparent quantitative differences up to two orders of magnitude in some cases. There are, however, indications that the lattice results can be utilized to improve the model predictions. Nevertheless, discrepancies between the lattice and nonlattice calculations need to be understood better to have a solid insight into the dynamics of the heavy sector. Furthermore, reliably determined charmed baryon observables would be invaluable input to investigate the nature of exotic states, which further emphasizes the importance of rigorous, first-principles calculations to advance our understanding of the dynamics of the heavy quarks and strong interactions. [ABSTRACT FROM AUTHOR]

We have reported the electronic, magnetic and optical properties of carbon doped bilayer hexagonal boron nitride (h‐BN) using thedensity functional theory. A single C‐doping at B/N sites gives the large band gap similar to dilute magnetic semiconducting behaviour with a finite net magnetic moment of 1.001 and 0.998μB, respectively. For double doping at B/N sites the net magnetic moment increases to 1.998 and 1.824μB, respectively. Upon C‐doping at N‐site, we obtained transition from non‐magnetic semiconductor (pristine) → magnetic semiconductor (1C) → half‐metal ferromagnetic (2C) → metal (3C). In case of the B site, we observed metallic behaviour for 2C‐doping. As 1,2 C‐doping at the B site reduces the energy band gap from 1.8 eV to 0.81 eV, falls in the visible range and offers an opportunity to utilized as a photocatalyst material. C‐doped systems show a magnetic semiconducting behavior crucial for spintronic applications. [ABSTRACT FROM AUTHOR]

The magnetic moment of a spherical superconductor that is located on the axis of the external axisymmetric magnetic field is found. It is proved that the magnetic moment is completely determined by the value of the external field in the center of the ball. [ABSTRACT FROM AUTHOR]

We report on the electronic structure and magnetic properties of hybrid heterostructures combined the ferromagnetic double perovskite Sr2CrOsO6 (SCOsO) and ferroelectric BaTiO3 (BTO) calculated in the GGA approach using the fully relativistic spin-polarized Dirac LMTO method. The electronic band structure is studied in the BTO and SCOsO oxides as well as in SCOsO/BTO hetero structures with different supercells: (1 × 1 × 1) monolayered, (2 × 2 × 1), and (1 × 1 × 2) SCOsO/BTO heterostructures. The optical and magneto-optical spectra of pure BTO and SCOsO oxides as well as of the SCOsO/BTO heterostructures are investigated theoretically and compared with avaliable experimental data. The element-specific x-ray absorption spectra as well as the x-ray magnetic circular dichroism at the Ti, Ba, and Os L2,3 edges in SCOsO/BTO heterostructures are investigated theoretically. Good agreement with experimental spectra has been found. [ABSTRACT FROM AUTHOR]

We report on the electronic structure and magnetic properties of hybrid heterostructures combined the ferromagnetic double perovskite Sr2CrOsO6 (SCOsO) and ferroelectric BaTiO3 (BTO) calculated in the GGA approach using the fully relativistic spin-polarized Dirac LMTO method. The electronic band structure is studied in the BTO and SCOsO oxides as well as in SCOsO/BTO hetero structures with different supercells: (1 × 1 × 1) monolayered, (2 × 2 × 1), and (1 × 1 × 2) SCOsO/BTO heterostructures. The optical and magneto-optical spectra of pure BTO and SCOsO oxides as well as of the SCOsO/BTO heterostructures are investigated theoretically and compared with avaliable experimental data. The element-specific x-ray absorption spectra as well as the x-ray magnetic circular dichroism at the Ti, Ba, and Os L2,3 edges in SCOsO/BTO heterostructures are investigated theoretically. Good agreement with experimental spectra has been found. [ABSTRACT FROM AUTHOR]

In this work, fabrication of Gd3+ substituted nickel spinel ferrite (NiGdxFe2-xO4) nanoparticles was carried out via co-precipitation route. X-ray powder diffraction (XRD) confirmed the spinel cubic structure of NiGdxFe2-xO4 nanoparticles. XRD data also facilitated to determine the divalent and trivalent metal cations distribution at both A and B sites of the ferrite lattice. Site radii, hopping and bond lengths were also calculated from XRD data. The spectral studies elucidated the formation of cubic spinel ferrite structure as well as stretching vibrations of M–O (metal–oxygen) bond at A and B sites of ferrites, represented by two major bands υ1 and υ2 respectively. FESEM analysis confirmed the irregular morphology of NiGdxFe2-xO4 nanoparticles. EDX spectrographs estimated the elemental compositions. The dielectric attributes were explained on the basis of the Debye-relaxation theory and Koop’s phenomenological model. At higher applied frequencies (AC) no prominent dielectric loss was observed. Magnetic parameter variations can be attributed to the substitution of the rare earth cations having larger ionic radii as compared to the radii of Fe3+ ions. Moreover, spin canting, magneto-crystalline anisotropy and exchange energy of electrons also helped in magnetic evaluation. Due to small coercivity values NiGdxFe2-xO4 nanoparticles can be employed significantly in high-frequency data storage devices.

It is interesting to understand the effect of defects in 2D materials because vacancy defects in 2D materials have novel electronic and magnetic properties. In this work, we studied electronic and magnetic properties of 1S vacancy defect (1Sv-MoS2), 2S vacancy defects (2Sv-MoS2), 1Mo vacancy defect (Mov-MoS2), and (1Mo & 1S) vacancy defects ((Mo-S)v-MoS2) in 2D MoS2 material by first-principles calculations within spin-polarized density functional theory (DFT) method. To understand the electronic properties of materials, we have analyzed band structures and DOS calculations and found that 1Sv-MoS2 & 2Sv-MoS2 materials have semiconducting nature. This is because, 1Sv-MoS2 & 2Sv-MoS2 materials open a small energy band gap of values 0.68 eV & 0.54 eV respectively in band structures. But, in Mov-MoS2 & (Mo-S)v-MoS2 materials, energy bands around the Fermi level mix with the orbital’s of Mo and S atoms. As a result, bands are split and raised around and above the Fermi energy level. Therefore, Mov-MoS2 & (Mo-S)v-MoS2 materials have metallic nature. We found that MoS2, 1Sv-MoS2 & 2Sv-MoS2 materials have non-magnetic properties, and Mov-MoS2 & (Mo-S)v-MoS2 materials have magnetic properties because magnetic moment of MoS2, 1Sv-MoS2 & 2Sv-MoS2 materials have 0.00 µB/cell value and Mov-MoS2 & (Mo-S)v-MoS2 materials have 2.72 µB/cell & 0.99 µB/cell respectively. Therefore, non-magnetic MoS2 changes to magnetic Mov-MoS2 & (Mo-S)v-MoS2 materials due to Mo and (1Mo & 1S) vacancy defects. The magnetic moment obtained in Mov-MoS2 & (Mo-S)v-MoS2 materials due to the distribution of up and down spins in 4p, 4d & 5s orbitals of Mo atoms and 3s & 3p orbitals of S atoms in structures. The significant values of the magnetic moment are given by distributed spins in 4d orbital of Mo atoms and 3p orbital of S atoms. BIBECHANA 18 (2) (2021) 68-79

Rare earth (RE)-based MgCu 2 -type intermetallic compounds are studied by first-principles calculations to search their spintronic applications and thermodynamic stability. We found in our observations that both EuPt 2 and GdPt 2 have half-metallic properties. The band gap arises in spin-down channel which is found to be enhanced when we move from EuPt 2 (0.91 eV) to GdPt 2 (1.04 eV). From magnetic properties we got to know that the magnetic moments of RE and Pt are opposite in direction and total magnetic moment is found to be 7.01 μ B and 4.1 μ B for EuPt 2 and GdPt 2 respectively. Presence of 5 d 1 electron in Gd valance shell is the reason for this difference in magnetic moments. No negative frequency has been observed in the phonon dispersion curve of both systems indicating the dynamic stability of MgCu 2 -type structure. Several thermodynamical potentials are also explored in the present study using quasiharmonic approximation. The half-metallicity of dynamically stable REPt 2 systems is appropriate for spintronic applications. [ABSTRACT FROM AUTHOR]

The paper investigated the Zigzag GaN nanoribbons (ZGaNNR) using the density functional theory(DFT) and non equilibrium Green's function(NEGF) framework. We have calculated the structural, electronic and transport properties of various Fe-ZGaNNR configurations. Based on the binding energy( E B ) calculations, Fe-doped@Ga_edge ZGaNNR(-6.51eV) is observed to be most structurally stable among different configurations. Our findings show the substitutional Fe passivation provides a stable bonding as compared to pristine configuration. The magnetic moment of different configurations depends upon the position of Fe atom. The discontinuity is observed in degenerative states of spin modes and same is follows by their respective density of states(DOS) and projected density of states(PDOS). Fe-termination@N_edge ZGaNNR is found to be a strong candidate for magnetic stabilization. High metallicity is observed in Fe-termination@both_the_edges ZGaNNR configuration. Further same is verified through current-voltage characteristics as current follow the pure linear behaviour. The practical application of the work on ZGaNNR can serve as a potential candidate for future low bias nanoscale spitronic devices and low power high speed interconnect applications. [ABSTRACT FROM AUTHOR]

The magnetically assembled chain-like structures of magnetic nanoparticles attract great attention due to their unique properties. In this paper, we studied the influences of essential magnetic controlling parameters on the chain-like structures of magnetic nanoparticles with diameter d = 360 nm using a 3D Monte Carlo simulation. The magnetic moment and volume fraction of magnetic nanoparticles were found to play crucial roles in the arrangement of the nanoparticles. The simulation results were in agreement with experimental evidence, summarized as follows: In the limit of low magnetic moment m < 3.7×10−16 A∙m2, magnetic nanoparticles did not linearly arrange along the direction of the magnetic field but formed aggregates. At magnetic moment m > 1.5×10−15 A∙m2 and volume fraction φ<0.02%, the formation effect of nanochains consisting of individual particles was first enhanced and then remained almost unchanged with increasing magnetic moment. For magnetic moment m>7.3×10−15 A∙m2 and volume fraction φ>1%, nanochains gradually coarsened into the nanobundles with increasing volume fraction. The results can provide a theoretical basis to construct and regulate other assembled structures consisting of building blocks. [ABSTRACT FROM AUTHOR]

Dielectric and magnetic properties of the Nd2– xCexCuO4 + δ bulk single crystal with x = 0.1 are studied in this work. The anisotropy of the field and temperature dependences of the specific magnetization is found. The value of specific magnetization measured in the magnetic field applied in parallel to CuO2 planes is higher than that measured in the magnetic field applied perpendicular to the planes; this is related to the additional contribution of magnetic moments of neodymium ions. In this case, at temperatures T < 100 K, when the magnetic field H is perpendicular to CuO2 planes, an area of antiferromagnetic coupling of ions exists within the CuO2 planes, which is not observed in the case of the parallel orientation of the magnetic field with respect to the CuO2 planes. Microwave studies show the existence of strong permittivity dispersion, which indicates the presence of natural resonance frequency, whose value is beyond the frequency range of performed measurements. [ABSTRACT FROM AUTHOR]

Taiji-1's in-orbit magnetic property is significant for the improvement of the satellite's attitude-control performance and the acceleration noise model of gravitational reference sensor. Test data of satellite drifts have been used to construct the model including interaction among the magnetic field; remnant magnetic moment and induced magnetic moment so as to estimate the satellite's magnetic property. Using the global optimization method, the remnant magnetic moment of Taiji-1 is estimated to be (-1.42 -0.19 -0.06) Am2. [ABSTRACT FROM AUTHOR]

• Non-stoichiometric NiFe 2 O 4 nanoparticles were sintered at different temperatures. • The Fe occupancy of the tetrahedral sites is greater than that of the octahedral ones. • There are cationic vacancies at octahedral sites. • The recoilless f -factor was calculated in the range of 5–300 K. • Thermal properties depend on the sintering temperature and non-stoichiometry. Temperature is one of the key parameters in the synthesis of a system of magnetic nanoparticles and can affect considerably the arrangement of atoms in the crystal structure. Consequently, the magnetic, elastic, and structural properties are strongly impacted. In the magnetically soft NiFe 1.8 O 4 spinel ferrite, the relative number of Ni and Fe ions in each of the two possible different geometries, tetrahedral (T) and octahedral (O), is of extreme importance. In this work, this material was studied on products of co-precipitation synthesis followed by a temperature dependent sintering. We performed 57Fe Mössbauer spectroscopy (MS), X-ray diffraction (XRD), scanning and transmission electron microscopies (SEM and TEM), X-ray absorption spectroscopy (XAS) using synchrotron radiation at Ni K- and L 2 -edge, and vibrating sample magnetometry (VSM) measurements. From XAS measurements it was found that Ni atoms prefer an octahedral coordination when the sintering temperature is increased. MS showed that the T-sites are more populated by Fe ions than the O-sites, a fact that can be explained by the presence of Fe ion vacancies in the O- sites. However, as the sintering temperature increases, we found that there is also a migration of Fe atom to the O-sites. Additionally, based on MS measurements in 78–292 K region, we estimated the Debye temperatures of the Fe ions in the tetra- and octahedral geometries and found that the recoiless f -factor depends on the sintering temperature of the nickel ferrite powders. The ratio f O / f T is about 0.98 and 0.95 at room temperature for the samples sintered at 1000 °C and 600 °C, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pressure can effectively tune the austenite phase stability of magnetic Ni 2 MnTa. • The volume change during martensitic phase transition is up to −4 %. • The enhanced interatomic interaction is responsible for the large volume change. • The large volume changes during transition could result in interesting properties. The creation of innovative functional materials with outstanding overall performance is the main challenge encountered in practical application. This study investigated the pressure-dependent martensitic phase transition in ductile compound Ni 2 MnTa and also revealed its physical mechanism. Theoretically, when pressure was applied, the martensitic phase transition in Ni 2 MnTa was accompanied by a significant volume change of −4 %. The results indicate that the inherent volume contraction leads to enhanced interatomic d – d orbital hybridization during the tetragonal deformation, a process in which thermodynamic driving force increases significantly and deformation ability is subsequently enhanced. Their synergistic interaction induced the large-volume-change martensitic transformation in ductile all- d -metal Heusler compound Ni 2 MnTa. A metamagnetic martensitic phase transition could occur due to the magnetic moment difference between the austenite and marensite phases. Practically and importantly, Ni 2 MnTa shows better ductile properties. The combination of excellent ductility and potential large-volume-change martensitic transformation in Ni 2 MnTa makes it an interesting candiade material. This study can provide significant research guidance for exploring and developing novel materials for future industrial application. [ABSTRACT FROM AUTHOR]

Minkov et al. (2022) claims to show magnetization measurements that demonstrate that sulfur hydride and lanthanum hydride under pressure are high temperature superconductors. In Hirsch and Marsiglio (2023), it was pointed out that Figs. 3a and 3e of Minkov et al. (2022) in its original form, Ref. [3], were inconsistent with each other according to the figure caption and text in Ref. [3]. Recently, the authors of Minkov et al. (2022) published an "Author Correction" Minkov et al. (2023) to the original form of Minkov et al. (2022) explaining that several linear transformations were used to obtain the data published in Fig. 3a from measured data published in Fig. 3e. Here I show that data shown in Fig. 3a of Minkov et al. (2022) are not related by a n y set of linear transformations to data published in Fig. 3e of Minkov et al. (2022), contrary to what is stated in the "Author Correction" Minkov et al. (2023) and in the corrected Minkov et al. (2022). Implications of this finding are discussed. • The published data are not related by linear transformations to the measured data. • This invalidates the conclusions in the paper. • Authors need to comply with the paper's Data Availability Statement. [ABSTRACT FROM AUTHOR]

• This work shows a simple and profound magnetic study of novel ZnO Buckyball structures. • The study includes magnetic properties of metal-doped (Al, Ag, Co, and Fe) ZnO Buckyball structure. • Variations in design, as well as a doping element, modified the magnetic behavior. • A small magnetic moment was observed in the ZnO-bb with non-magnetic dopant atom Al and Ag. • A comparatively large amount of magnetic moments were observed with magnetic dopants like Co and Fe. Magnetic properties of metal-doped ZnO buckyball 'X@(ZnO-bb)' structure have been investigated using first-principle density functional theory. Different structures of ZnO Buckyball, with the dopant atom X(Where X = Al, Ag, Fe, and Co) have been studied. To understand if the magnetic properties are arising fully due to the dopant atoms or because of the structural variation or intrinsic defects, the Zn and O atom is placed at the center of ZnO-bb, instead of other dopants. This study claims a novel ZnO-bb structure whose magnetic properties are reported for the first time, to the best of our knowledge. The change in the design of the structure, as well as the doping atom, led to variations in the magnetic properties of ZnO. A small amount of magnetic moment was observed in the ZnO-bb with non-magnetic dopant atoms like Al and Ag. Furthermore, a comparatively large amount of magnetic moments were observed with magnetic atoms like Co and Fe. The presence of a small amount of magnetic moment in the X@(ZnO-bb) structure unwraps a scope to further study this novel structure with different dopant atoms for various applications. A possible mechanism for the initiation of structure-based magnetism is also discussed. When the Zn or O atoms are placed at the center of ZnO-bb, a small amount of magnetic moment is observed in the O@(ZnO-bb) structure. This work systematically studies the magnetic properties in the ZnO-bb structure, which can be used for various applications like analog and digital data storage, magnetic therapy, and devices used in medical fields like MRI, etc. [ABSTRACT FROM AUTHOR]

We have investigated the electronic and magnetic properties of one-dimensional Sr 3 CuIrO 6 , Sr 3 ZnIrO 6 , and Sr 3 CuPtO 6 oxides within the density-functional theory (DFT) using the generalized gradient approximation while taking into account strong Coulomb correlations (GGA+ U) in the framework of the fully relativistic spin-polarized Dirac linear muffin-tin orbital band-structure method. The strong spin–orbit coupling (SOC) in these oxides splits the t 2 g -type manifold into a lower j e f f = 3/2 quartet and an upper j e f f = 1/2 doublet. The j e f f = 1/2 band is almost completely given by linear combinations of d 5 / 2 states. The occupied j e f f = 3/2 band is dominated by d 3 / 2 states with some weight of d 5 / 2 states. We have investigated theoretically the resonant inelastic x-ray scattering (RIXS) spectra at the Ir and Pt L 3 edges in Sr 3 CuIrO 6 , Sr 3 ZnIrO 6 , and Sr 3 CuPtO 6. The experimentally measured RIXS spectrum of Sr 3 CuIrO 6 possesses a sharp feature below 1.3 eV corresponding to transitions within the Ir t 2 g levels. The excitation located from 3 eV to 5 eV is due to t 2 g → e g transitions. The next two high energy structures appear due to d − d transitions between the charge transfer Ir 5 d ct states and t 2 g and e g states. The theoretically calculated RIXS spectra of Sr 3 ZnIrO 6 and Sr 3 CuIrO 6 at the Ir L 3 edges are very similar due to the similarity of their energy band structures. The RIXS spectrum at the Pt L 3 edge of Sr 3 CuPtO 6 significantly differs from the corresponding spectra at the Ir L 3 edge of Sr 3 CuIrO 6 and Sr 3 ZnIrO 6. There are not any intra- t 2 g transitions in Sr 3 CuPtO 6 due to fully occupied t 2 g states. Besides, there are additional 5 d Cu → e g transitions, where the 5 d Cu states are derived from the tails of the Cu 3 d states inside the Pt atomic spheres. • Sr 3 CuIrO 6 can be classified as a J e f f = 1 / 2 Mott isolator. • The calculations with U e f f = 1 eV give the best description of the RIXS spectra. • The high energy RIXS structure is derived from ligand-to-Ir5d transitions. [ABSTRACT FROM AUTHOR]

The efficiency of a magnetic system of kinetic moment dumping in solving the problem of stabilizing Aist-2D spacecraft without using information on angular velocity is investigated. We defined the conditions under which the magnetic moment produced by electromagnets constitutes a useful control mechanical moment. Boundary conditions for preventing emergence of the parasitic moment are also defined. The paper presents the solution of the problem of forming the vector of the kinetic moment of the system “spacecraft + control moment gyro” according to the information on the vector of geomagnetic induction of the Earth. We defined the dependence of the time taken by the algorithm of angular speed reduction on the value and direction of the projections of the vector of spacecraft angular speeds at the time of algorithm actuation. The results obtained in the course of mathematical modeling and natural experiment on the spacecraft, the process of dumping angular speeds in providing the solution of the problem of attitude determination with the use of star sensors are compared.

Electronic structure and magnetic properties of Fe3Se4 are calculated using the density functional approach. Due to the metallic properties, magnetic moments of the iron atoms in two nonequivalent positions in the unit cell are different from ionic values for Fe3+ and Fe2+ and are equal to M1=2.071μB and M2=−2.042μB, making the system ferrimagnetic. The total magnetic moment for the unit cell is 2.135μB. Under isotropic compression, the total magnetic moment decreases non-monotonically and correlates with the non-monotonic dependence of the density of states at the Fermi level N(EF). For 7% compression, the magnetic order changes from the ferrimagnetic to the ferromagnetic. At 14% compression, the magnetic order disappears and the total magnetic moment becomes zero, leaving the system in a paramagnetic state. This compression corresponds to the pressure of 114 GPa. The magnetic ordering changes faster upon application of an isotropic external pressure due to the sizeable anisotropy of the chemical bondings in Fe3Se4. The ferrimagnetic and paramagnetic states occur under pressures of 5.0 and 8.0 GPa, respectively. The system remains in the metallic state for all values of compression.

Z-type hexagonal ferrites have recently received attention for their room-temperature magnetoelectric (ME), which is activated when the temperature at which the transverse-conical spin-state transitions to a ferrimagnetic state is increased. The changes in the magnetic domain structure at the transition have been well-documented; however, they are still not understood in detail. In the present study, Lorentz transmission electron microscopy (TEM) analysis combined with an in situ heating experiment was conducted to demonstrate the shift in magnetic domain structure during the transition from the transverse-conical spin arrangement to a ferrimagnetic spin order. The dynamics of the magnetic domain structure changes with the increasing temperature were acquired in real-time. At 490 K, the magnetization transition from the transverse-conical spin state to the ferromagnetic state was demonstrated. Cross-tie domain walls formed during the magnetic transition process. The increased effect of the demagnetizing field applied to the 180° magnetic domains was caused by a lower magnetocrystalline anisotropy (MCA) at the easy axis of magnetization.