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A giant exchange bias is detected in the colossal magnetoresistance of Nd2/3Ca1/3MnO3 perovskite at low temperatures and is evidence of intrinsic exchange coupling in this compound. These phenomena confirm our previous assumption that the low-temperature magnetic structure of this compound consists of small (nanosized) ferromagnetic clusters embedded in a charge-ordered antiferromagnetic matrix. The magnetic behavior of the perovskite Nd2/3Ca1/3MnO3 is consistent with a cluster-glass magnetic state and inconsistent with the classical spin-glass state observed in a variety of disordered magnetic systems. We think that the cluster-glass magnetic behavior of Nd2/3Ca1/3MnO3 originates in a self-organized phase-separated state of the compound. A Cole-Cole analysis of the dynamic susceptibility at low temperatures reveals an extremely broad distribution of relaxation times, indicating that spins are frozen on a 'macroscopic' time scale. Slow relaxation of the zero-field-cooled magnetization is also observed experimentally. This slow relaxation confirms the cluster-glass magnetic state of the compound. Two highly different relaxation mechanisms have been found: the first is characteristic of temperatures below the freezing temperature Tg ∼ 60 K and the second, of higher temperatures. [ABSTRACT FROM AUTHOR]

The temperature dependence of the thermal conductivity k(T) of the AsxS100-x glass system was studied down to 1.8 K in a wide range of various (x = 20, 28.6, 40, 45, and 50) compositions. Universal glass anomalies in k(T) were revealed. The temperature dependence k(T) ∼ T2 onset at the lowest temperatures and plateau below 15 K were detected. The plateau formation is sample quality sensitive and composition-dependent. It was experimentally found that even with a slow cooling rate, several samples were cracked. Depending on the sample damage, the additional internal scattering process leads to the k(T) plateau suppression. The observed k(T) temperature dependence is similar to the glassy ceramics-like behavior. [ABSTRACT FROM AUTHOR]

The annealing behavior of (1-x)BiMg0.5Ti0.5O3–xBiZn0.5Ti0.5O3 [(1-x)BMT–xBZT] perovskite solid solutions synthesized under high pressure was studied in situ via X-ray diffraction and piezoresponse force microscopy. The as prepared ceramics show a morphotropic phase boundary (MPB) between the non-polar orthorhombic and ferroelectric tetragonal states at 75 mol. % BZT. It is shown that annealing above 573 K results in irreversible changes in the phase diagram. Namely, for compositions with 0.2 < x < 0.6, the initial orthorhombic phase transforms into a ferroelectric rhombohedral phase. The new MPB between the rhombohedral and tetragonal phases lies at a lower BZT content of 60 mol. %. The phase diagram of the BMT–BZT annealed ceramics is formally analogous to that of the commercial piezoelectric material lead zirconate titanate. This makes the BMT–BZT system promising for the development of environmentally friendly piezoelectric ceramics. [ABSTRACT FROM AUTHOR]

• The glasses of As x S (100-x) with x = 20, 28.6, 45, 40, 50 were prepared. • Specific heat C p / T 3 shows a nonlinear dependence of boson peak (BP) on composition. • Longitudinal elastic moduli, Raman spectroscopy and C p / T 3 depend on composition. • Correlation between type of nanocluster and C p / T 3 was found in As x S (100-x) glasses. • Ring-like and branchy-like nanoclusters are a possible origin of BP. The combination of mean coordination and concentration dependencies of elastic modules and low-frequency Raman scattering of As-S glasses brings new information about the spectroscopic boson peak (SBP) behavior. The analysis of the characteristic temperature positions of the thermometric boson peak (TBP) and the magnitude of heat capacity of As-S glasses was performed. This study was focused on the As-S compounds from the first glass-forming region with particular attention to the compositions of flexible, intermediate, and stressed-rigid phases. The origin of SBP and TBP is expected to have a structural nature. The spectral features found in the super low-frequency region of Raman spectra were assigned to quasi-localized "soft" modes. The sulfur-rich glass, g -As 2 S 5 , represents the intermediate phase with As n S m clusters containing closed ends and several "soft" nanoclusters. These soft clusters can be responsible for intrinsic quasi-localized "soft" modes, the overall rigidity of the system, and quasi-elastic light scattering. [ABSTRACT FROM AUTHOR]

Precipitation of nanocrystallites of cobalt–aluminium layered double hydroxides in a magnetic field has been studied. In a magnetic field perpendicular to the substrate, dense and homogeneous films have been obtained. Magnetic anisotropy of the crystallites is explained by deviation from the statistical cation distribution in favour of honeycomb-like coordination of cobalt. [ABSTRACT FROM AUTHOR]

Comparative analysis of experimentally measured Raman spectra of crystalline (c), glassy (g), and powdered c‐As2S3 samples is performed based on vibrational modes of As6S6+6/2 ring‐like nanoclusters being fully ("rigid") or partially ("soft") interconnected with the glassy matrix, calculated using density functional theory (DFT). Although good agreement is found in the 100–500 cm−1 spectral range, the DFT simulations show additional super‐low frequency modes of "soft" rings at wavenumbers being significantly lower than the "rigid" ring's vibrational band at 26 cm−1. Broadening of the relatively narrow low‐frequency band of "rigid" clusters is found to be dependent on the number of interconnections of "soft" clusters with the glassy matrix, demonstrating mixing of "rigid" and "soft" vibrations in the boson peak region of g‐As2S3. In addition, the shift of the super‐low frequency Raman modes of "soft" nanoclusters and equivalent characteristic temperature are found to be nonlinearly dependent on the number of interconnections. Comparison with experimental Raman spectroscopic and heat capacity data indicates that the main contribution of both the LF Raman intensity and the low‐temperature anomaly of specific heat at 5.3 K comes from "soft" clusters with four and two interconnections. [ABSTRACT FROM AUTHOR]

Exchange bias (EB) phenomena have been observed in Nd2/3Ca1/3MnO3 colossal magnetoresistance perovskite below the Curie temperature TC~70K and attributed to an antiferromagnetic-ferromagnetic (FM) spontaneous phase segregated state of this compound. Field cooled magnetic hysteresis loops exhibit shifts toward negative direction of the magnetic field axis. The values of exchange field HEB and coercivity HC are found to be strongly dependent of temperature and strength of the cooling magnetic field Hcool. These effects are attributed to evolution of the FM phase content and a size of FM clusters. A contribution to the total magnetization of the system due to the FM phase has been evaluated. The exchange bias effect decreases with increasing temperature up to TC and vanishes above this temperature with disappearance of FM phase. Relaxation of a non-equilibrium magnetic state of the compound manifests itself through a training effect also observed while studying EB in Nd2/3Ca1/3MnO3. [ABSTRACT FROM AUTHOR]

We report a new antiferromagnetic radical‐anion salt (RAS) formed from 7,7,8,8‐tetracyanquinonedimethane (TCNQ) anion and 2‐amino‐5‐chloro‐pyridine cation with the composition of (N−CH3−2‐NH2−5Cl−Py)(TCNQ)(CH3CN). The crystallographic data indicates the formation of (TCNQ)2.− radical‐anion π‐dimers in the synthesized RAS. Unrestricted density functional theory calculations show that the formed π‐dimers characterize with strong π‐stacking "pancake" interactions, resulting in high electronic coupling, enabling efficient charge transfer properties, but π‐dimers cannot be stable in the isolated conditions as a result of strong Coulomb repulsions. In a crystal, where (TCNQ)2.− π‐dimers bound in the endless chainlets via supramolecular bonds with (N−CH3−2‐NH2−5‐Cl−Py)+ cations, the repulsion forces are screened, allowing for specific parallel π‐stacking interactions and stable radical‐anion dimers formation. Measurements of magnetic susceptibility and magnetization confirm antiferromagnetic properties of RAS, what is in line with the higher stability of ground singlet state of the radical‐anion pair, calculated by means of the DFT. Therefore, the reported radical‐anion (N−CH3−2‐NH2−5Cl−Py)(TCNQ)(CH3CN) solvate has promising applications in novel magnetics with supramolecular structures. [ABSTRACT FROM AUTHOR]

A post-synthesis thermal treatment of metastable phases in the high-pressure stabilised perovskite BiFe1−yScyO3 system results in the irreversible formation of polymorphs which represent novel polar and antipolar structures with interesting magnetic properties. Such annealing-stimulated polymorphism is believed to be a general phenomenon which can be found in other systems. [ABSTRACT FROM AUTHOR]

An experimental study is presented of the rotational magnetocaloric effect in a KTm(MoO 4 ) 2 single crystal at temperatures above 2 K associated with the rotation of a single crystal between the magnetic easy and hard axis in constant magnetic fields up to 5 T. The magnetocaloric properties of KTm(MoO 4 ) 2 single crystals are investigated by isothermal magnetization measurements. The maximal rotational entropy change −Δ S R  ≈ 9.8 J/(kgK) is achieved at 10 K in a magnetic field of 5 T. The adiabatic rotation of a single crystal in a field of 5 T at an initial temperature of 4.2 K causes cooling of the sample down to 0.5 K, which indicates an interesting possibility of using this material for cooling processes at low temperatures. [ABSTRACT FROM AUTHOR]

From the aqueous-methanolic systems Ni(NO 3 ) 2 – LiTCNQ – 5,5′- dmbpy and Ni(NO 3 ) 2 – LiTCNQ – 4,4′- dmbpy three novel complexes [Ni(5,5′ -dmbpy ) 3 ](TCNQ) 2 ( 1 ), [Ni(4,4′ -dmbpy ) 3 ](TCNQ) 2 ( 2 ) and [Ni(4,4′- dmbpy ) 3 ] 2 (TCNQ-TCNQ)(TCNQ) 2 ∙0.60H 2 O ( 3 ), were isolated in single crystal form. The new compounds were identified using chemical analyses and IR spectroscopy. Single crystal studies of all samples corroborated their compositions and have shown that their ionic structures contain the complex cations [Ni(5,5′- dmbpy )] 2+ ( 1 ) or [Ni(4,4′- dmbpy )] 2+ ( 2 and 3 ). The anionic parts of the respective crystal structures 1 – 3 are formed by TCNQ ⋅- anion-radicals and in 3 also by a σ-dimerized dianion (TCNQ-TCNQ) 2- with a C-C distance of 1.663(5) Å. The supramolecular structures are governed by weak hydrogen bonding interactions. The variable-temperature (2–300 K) magnetic studies of 1 and 3 confirmed the presence of magnetically active Ni(II) atoms with S  = 1 and TCNQ ⋅- anion-radicals with S  = 1/2 while the (TCNQ-TCNQ) 2- dianion is magnetically silent. The magnetic behavior was described by a complex magnetic model assuming strong antiferromagnetic interactions between some TCNQ ⋅- anion-radicals. [ABSTRACT FROM AUTHOR]

The agriculture sector is the principal source of income for around 20% of the EU-26 population, which live in predominantly rural regions that would be devastated without its contribution. Moreover, the combined agricultural and food sector forms an important part of the EU economy, accounting for 15 million jobs (8.3% of total employment) and 4.4% of GDP. The 12 million active farmers across Europe today, have an average farm size of about 15 ha, and are expected to meet the needs of 500 million Europeans. In addition, they are also expected to promote a sustainable and balanced development of their land, also in areas where production conditions are difficult. Yet, despite the relevance of the sector, the use of land for agriculture purposes is not very sustainable. Among other issues, there is a serious problem in respect of the abandonment of agricultural land. Based on the perceived need for research on this topic, the aim of this paper is to examine the causes and consequences of agricultural land abandonment, outlining its social, economic and environmental impacts, as well as the implications for territorial integration. [ABSTRACT FROM PUBLISHER]

Magnetic behavior of CoII(n)AlIII layered double hydroxides (LDHs) (n=Co/Al=2 and 3) intercalated with nitrate was studied as a function of temperature. Both LDH compounds are paramagnetic above about 8K. A rapid increase of their magnetic moments occurs below this temperature until the moments reach the maximum values at Tmax of 4.0K and 3.2K for Co(2)Al-NO3 and Co(3)Al-NO3, respectively. Below Tmax, the zero-field-cooled and the field-cooled static magnetization curves are strongly different. Along with this low-temperature phenomena, Co(2)Al-NO3 and Co(3)Al-NO3 demonstrate anomalous behavior of their temperature dependence magnetic susceptibility in a highertemperature range: between 75 and 175K, both the paramagnetic Curie temperature and the effective magnetic moment change in a non-monotonous way. Possible structural reasons of the observed magnetic behavior of the CoII(n)AlIII LDHs are discussed. [ABSTRACT FROM AUTHOR]

• Nanocluster's contribution to the low-temperatures anomalies in As-S glasses. • Raman spectroscopy revealed g (ω) ∼ ω 2 dependence at ultra-low frequencies. • Specific heat C p/ T 3 showed Boson peak about T ∼ 5 K. • Nanoclusters produce thermal conductivity plateau and boson beak. • Ring-like and branchy-like nanoclusters are responsible for boson peak. A plateau characterizes the thermal conductivity k (T) of many amorphous materials at temperatures above 1 K together with a maximum in specific heat C p , called the Boson peak at the same temperature region. It has been believed for over 50 years that those features are the universal property of glasses. Using the analogy of the keystone species concept of ecology, where one species has a disproportionately large effect on its environment relative to its abundance, we will present the impact of keystone nanocluster concentration on low-temperature k (T). Our study is focused on the As-S glassy systems, where each compound represents a different environment. It is shown that the presence of keystone S 8 nanoclusters leads to the plateau formation in the k (T) of As 2 S 3 and As 2 S 5 samples. At the same time, the Boson peak in the C p was preserved, suggesting that nanoclusters contribute to both the k (T) plateau and C p maximum. [ABSTRACT FROM AUTHOR]

There are many definitions for the term Corporate Social Responsibility (CSR), but it can broadly be understood as a commitment that an organization must have towards society, expressed through actions and attitudes that affect it positively. In Latin America, in particular, this field is still at an initial stage, and few companies have actually developed and integrated CSR practices as part of their management system. This paper aims to present a set of CSR initiatives and projects developed by a Brazilian aircraft manufacturer, Embraer, considered an example of best practice in sustainable management practices. The paper also verifies if these activities are integrated into the company's management model in a mature way, as proposed by the literature. The research method used here was a case study with semi-structured interviews with a set of employees responsible for CSR at the company. The results gathered allow the projects developed at the company to be clustered around six main areas: excellence in education, social partnership programmes, entrepreneurship, corporate social responsibility, volunteering and preservation of the history of the Brazilian aeronautics industry. All these projects are exemplary managed and critically analyzed in relation to aggregation of value they provide to society, thus ensuring suitable results. As a conclusion of the survey, it was observed that Embraer has integrated the CSR practices with other existing management systems in a harmonious and mature form. The scientific value of this research lies in the presentation of CSR practices developed by one of the most important companies in Brazil, with a management system directed to excellence. Other companies and researchers can use these practices as a benchmark, or as examples of good CSR practice leading to tangible results. [ABSTRACT FROM AUTHOR]

Organo-metallic compounds Cu( en )(H 2 O) 2 SO 4 ( en =C 2 H 8 N 2 ) and Cu( tn )Cl 2 ( tn =C 3 H 10 N 2 ) representing S =1/2 quasi-two-dimensional Heisenberg antiferromagnets with an effective intra-layer exchange coupling J/ k B ≈3 K, have been examined by specific heat measurements at temperatures down to nominally 50 mK and magnetic fields up to 14 T. A comparative analysis of magnetic specific heat in zero magnetic field revealed nearly identical contribution of short-range magnetic correlations and significant differences were observed at lowest temperatures. A phase transition to long-range order was observed in Cu( en )(H 2 O) 2 SO 4 at T C =0.9 K while hidden in Cu( tn )Cl 2 . A response of both compounds to the application of magnetic field has rather universal features characteristic for a field-induced Berezinskii–Kosterlitz–Thouless transition theoretically predicted for ideal two-dimensional magnets. [ABSTRACT FROM AUTHOR]

Iron–chromium nanoparticles (NPs) were obtained through the thermal decomposition of μ 3 -oxo heterotrinuclear {FeCr 2 O} acetate in the presence of sunflower oil and dodecylamine (DA) as surfactants. The average diameter of the NPs was 3.5 nm, as estimated on the basis of transmission electron microscopy and atomic force microscopy images. Both techniques revealed the formation of roughly approximated spheres with some irregularities and agglomerations in larger spherical assemblies of 50–100 nm. In hexane, NPs with diameters in the 2.33–4.85 nm range are individually dispersed, as emphasized by dynamic light scattering measurements. The amorphous nature of the product was emphasized by X-ray powder diffraction. The study of the magnetic properties shows the presence of superparamagnetic state of iron–chromium oxide NPs and the diamagnetic contribution from DA layer forming a shell of NPs. [ABSTRACT FROM AUTHOR]

(1– x)BiMg 0.5 Ti 0.5 O 3 − x BiZn 0.5 Ti 0.5 O 3 [(1− x)BMT– x BZT] ceramics of perovskite solid solutions, in which BMT and BZT are lead-free structural analogs of PbZrO 3 and PbTiO 3 , respectively, have been synthesized under high pressure. It was found that the as-prepared compositions with a relative BZT content of <75 mol% are orthorhombic (space group Pnnm), while those with a BZT content above this value are tetragonal (P 4 mm). In the solution with x = 0.75, both phases coexist forming a morphotropic phase boundary (MPB). The compositional dependence of the normalized unit cell volume exhibits a ∼5% jump at x = 0.75. At the same time, the microstructure of the obtained (1– x)BMT− x BZT ceramics shows no particular variation with the chemical composition over MPB. Piezoresponse force microscopy measurements indicate the ferroelectric state of the studied materials and allowed one to estimate their intrinsic piezoelectric coefficients. [Display omitted] • The entire perovskite (1 –x)BMT– x BZT series has been synthesized under high pressure. • The orthorhombic-to-tetragonal morphotropic phase boundary was revealed at x = 0.75. • In the range of x = 0.75, the primitive perovskite unit-cell volume exhibits a 5% jump. • The (1– x)BMT– x BZT ceramics over the morphotropic phase boundary are all piezo-active. [ABSTRACT FROM AUTHOR]

The exchange bias (EB) phenomenon has been found in Nd2/3Ca1/3MnO3 perovskite. The phenomenon manifests itself as a negative horizontal shift of magnetization hysteresis loops. The EB phenomenon is evident of an interface exchange coupling between coexisting antiferromagnetic (AFM) and ferromagnetic (FM) phases and confirms the phase separated state of the compound at low temperatures. The EB effect is found to be strongly dependent on the cooling magnetic field and the temperature, which is associated with the evolution of spontaneous AFM-FM phase separated state of the compound. Analysis of magnetic hysteresis loops has shown that ferromagnetic moment M FM originating from the FM clusters saturates in a relatively low magnetic field about H ~ 0.4 T. The obtained saturation value MFM(1 T) ~ 0.45 µB is in a good agreement with our previous neutron diffraction data. [ABSTRACT FROM AUTHOR]

[Mn(L)(μ1,1-N3)2]2n[Mn(H20)2(μ1,1-N3)2]n (1) and [Cd(HL)(μ1,1-N3)2]n (2) have been synthe-sized from HL (HL: pyridine-2-carbaldehyde semicarbazone) and azide ligands, characterized by FT-IR, UV-vis spectroscopy and X-ray crystallography. Single crystal X-ray diffraction revealed that 1 is a coordination polymer consisting of two infinite 1-D chains: chain A with [Mn(L) (μ1,1-N3)2]2n and chain B with [Mn(H20)2(μ1,1-N3)2]n. In both chains, Mn centers are connected via two double end-on (EO) azide bridges. 2 is a coordination polymer consisting of a 1-D infinite chain, where Cd centers are connected via two double EO azide bridges. The electrochemistry of HL, 1 and 2 were studied by cyclic voltammetry. Magnetic susceptibility measurements indicate bulk ferromagnetic coupling for 1 below 5 K. Antimicrobial activities of both compounds 1 and 2 were greater than HL, with the strongest effect for 2 consistent with its larger radius and electronegativity of Cd(II) ions.[Mn(L)(n,i-N3)2]2„[Mn(H20)2(n1,-N3)2]„ (1) and [Cd(HLXnM-N3)2]„ (2) have been synthe-sized from HL (HL: pyridine-2-carbaldehyde semicarbazone) and azide ligands, characterized by FT-IR, UV-vis spectroscopy and X-ray crystallography. Single crystal X-ray diffraction revealed that 1 is a coordination polymer consisting of two infinite 1-D chains: chain A with [Mn(L) (Hi,i-N3)2]2„ and chain B with [Mn(H20)2(|i|,|-N3)2]„. In both chains, Mn centers are connected via two double end-on (EO) azide bridges. 2 is a coordination polymer consisting of a 1-D infinite chain, where Cd centers are connected via two double EO azide bridges. The electrochemistry of HL, 1 and 2 were studied by cyclic voltammetry. Magnetic susceptibility measurements indicate bulk ferromagnetic coupling for 1 below 5 K. Antimicrobial activities of both compounds 1 and 2 were greater than HL, with the strongest effect for 2 consistent with its larger radius and electronegativity of Cd(II) ions. [ABSTRACT FROM AUTHOR]

[Cu(bmen)2(H2O)2]F2∙4H2O (1) (bmen = N,N′-dimethylethane-1,2-diamine) and [Cu(bmen)2(BF4)2] (2) exhibit ionic and molecular crystal structures, respectively. In both1and2, Cu(II) exhibits tetragonally elongated six coordination in the 4 + 2 form with two chelatebmenin the equatorial plane; axial positions are occupied by weakly bound water in1while in2in these positions are fluorine from disordered BF4−. Packing in1and2are governed by hydrogen bonds (HBs). Magnetic studies from 1.8 to 300 K reveal that1and2follow the Curie–Weiss law with parametersθ = −0.88 K andg = 2.04 for1andθ = −0.58 K andg = 2.13 for2, suggesting the presence of weak antiferromagnetic interactions. [ABSTRACT FROM AUTHOR]

Abstract: We have studied by the electron-spin resonance (ESR) and static magnetic field techniques, the La2/3Ba1/3MnO3 perovskite, which was previously shown to exhibit a martensitic phase transformation in the vicinity of T s ∼200K [Physical Review B 68, 054109 (2003)], leading to its structural phase-segregated state. Resonant absorptions reveal that in the temperature interval from 100K to 340K the compound represents a mixture of two ferromagnetic phases possessing different magnetizations, in varying proportions depending on the temperature, and a small amount of a paramagnetic phase. The results agree well with the previous neutron diffraction study. Applied in the ESR experiments, magnetic fields (2–6kOe) strongly affect the magnetization curves: even magnetic field as high as 700Oe modifies the anomaly in the phase transformation region and removes the difference between the zero-field cooled and field-cooled magnetization curves, which implies that the difference in the magnetic susceptibility of the coexisting phases is small and the magnetic domain configuration can be easily changed. [Copyright &y& Elsevier]

Abstract: A detailed study of the low-temperature magnetic state and the relaxation in the phase-separated colossal magnetoresistance Nd2/3Ca1/3MnO3 perovskite has been carried out. Clear experimental evidence of the cluster-glass magnetic behavior of this compound has been revealed. Well defined maxima in the in-phase linear ac susceptibility χ′(T) were observed, indicative of the magnetic glass transition at T g ∼60K. Strongly divergent zero-field-cooled and field-cooled static magnetizations and frequency dependent ac susceptibility are evident of the glassy-like magnetic state of the compound at low temperatures. The frequency dependence of the cusp temperature T max of the χ′(T) susceptibility was found to follow the critical slowing down mechanism. The Cole–Cole analysis of the dynamic susceptibility at low temperature has shown extremely broad distribution of relaxation times, indicating that spins are frozen at “macroscopic” time scale. Slow relaxation in the zero-field-cooled magnetization has been experimentally revealed. The obtained results do not agree with a canonical spin-glass state and indicate a cluster glass magnetic state of the compound below T g , associated with its antiferromagnetic–ferromagnetic nano-phase segregated state. It was found that the relaxation mechanisms below the cluster glass freezing temperature T g and above it are strongly different. Magnetic field up to about μ 0 H∼0.4T suppresses the glassy magnetic state of the compound. [Copyright &y& Elsevier]

Abstract: The low temperature specific heat and magnetic characteristics of Nd2/3Ca1/3MnO3 perovskite are studied in a wide range of magnetic fields (up to 9T). Temperature dependent specific heat data show a broadened Schottky-like anomaly below 20K caused by splitting of the Nd3+ ions ground-state doublet in the effective molecular field H ex , determined by exchange interaction between Nd and Mn spin systems supplemented by an applied external magnetic field. Existence of the splitting at zero magnetic field and expressed field dependence is the evidence of a strong exchange coupling between Nd and Mn magnetic subsystems. The Nd-ions magnetic ordering leads to an additional contribution to the magnetic moment of the system below 30K, producing anomalies of the magnetic loss and field-cooled and zero-field-cooled magnetizations. The observed broadened Schottky-like anomalies are fitted for each applied magnetic field by the sum of three Schottky functions. Applied magnetic field extends the anomaly region and shifts it to higher temperatures. Splitting of the higher crystal field Kramers doublets gives an additional contribution to the heat capacity in magnetic fields. The ground state doublet g-factors g || and g ⊥ were estimated to be 3.4 and 2.2, respectively, and H ex was estimated to be 9T. The Nd3+ ions magnetic moment estimated from the magnetization data agrees with the value obtained from the specific heat data. [Copyright &y& Elsevier]

Abstract: The shifts of the magnetic and charge ordering transition temperatures caused by Nd substitution for Y in Nd2/3Ca1/3MnO3 CMR narrow-band perovskite manganite have been studied. At low temperatures, three different long-range magnetic orderings consistent with a phase separation scenario have been observed in the doped compound (Nd0.9Y0.1)2/3Ca1/3MnO3 by neutron-diffraction study: the antiferromagnetic orderings of PCE and DE types existing below ∼110 and ∼60K, respectively, and the ferromagnetic one of B type existing below ∼42. Magnetic phase transformations temperatures as well as those of charge ordering have been found to be structural-dependent. Y-doping leads to the decrease of the anisotropy of the orthorhombic Pnma crystal lattice b/√2c, which causes a decrease of the indirect exchange parameters in the system and thus a decrease in the magnetic transformation temperatures for 20–30K in the doped compound. Doping leads as well to the higher level of the coherent Jahn–Teller distortions of the MnO6 octahedra in the 200–300K temperature region, which results in the increase of the charge ordering temperature for ∼80K. [Copyright &y& Elsevier]

Abstract: The synthesis, structural analysis, spectroscopic studies, susceptibility and specific-heat measurements of {[Cu(bmen)2][Pt(CN)4]} n (bmen=N,N′-dimethylethylenediamine) are presented. X-ray crystal-structure analysis revealed that the [Pt(CN)4]2− building blocks are combined with [Cu(bmen)2]2+ units to form a chain-like structure along the a axis. The Cu(II) atoms are hexacoordinated by four nitrogen atoms in the equatorial plane belonging to two molecules of bidentate bmen ligands with average Cu–N distance of 2.043(18)Å. The axial positions are occupied by two nitrogen atoms from bridging [Pt(CN)4]2− anions at a longer axial Cu–N distance of 2.490(4)Å. The compound is characterized by the presence of a weak antiferromagnetic exchange coupling J/kB =0.6K. Despite the one-dimensional (1D) character of the structure, the analysis of the magnetic properties and specific heat at very low temperatures shows that [Cu(bmen)2][Pt(CN)4] behaves as a two-dimensional (2D) square-lattice Heisenberg magnet with weak interlayer coupling. [Copyright &y& Elsevier]

Abstract: Crystal structure, thermodynamic properties and electron spin resonance spectra of Cu(NH3)2Ag2(CN)4 have been studied. The structure of the studied compound consists of interpenetrating wave-shaped two-dimensional (2d) arrays, in which CuN4N2 octahedra axially elongated due to the Jahn–Teller effect are linked by diamagnetic [Ag(CN)2]− anions forming a square lattice. Although the susceptibility and specific heat data confirm the existence of short-range order at about 2K, quantitative analysis of the experimental data reveals that the magnetic behavior differs from that of the crystal structure expected for 2d Heisenberg magnet on the square lattice. Structural features responsible for the observed difference are discussed. In addition, it is suggested, that additional degrees of freedom contribute to the thermodynamic equilibrium properties in the millikelvin temperature range. [Copyright &y& Elsevier]

Abstract: Violet crystals of [Cu(en)2][Pt(CN)4] and blue crystals of [Cu(dmen)2][Pt(CN)4] were crystallized from the water–methanol solution containing CuCl2·2H2O, ethylenediamine (en) or N,N-dimethylethylenediamine (dmen) and K2[Pt(CN)4]·3H2O. Both compounds were characterized using elemental analysis, infrared and UV-VIS spectroscopy, magnetic measurements, specific heat measurements and thermal analysis. X-ray structure analysis revealed chain-like structure in both compounds. The covalent chains are built of Cu(II) ions linked by [Pt(CN)4]2− anions in the [111] and [101] direction, respectively. The Cu(II) atoms are hexacoordinated by four nitrogen atoms in the equatorial plane from two molecules of bidentate ligands L with average Cu–N distance of 2.022(2) and 2.049(4)Å, respectively. Axial positions are occupied by two nitrogen atoms from bridging [Pt(CN)4]2− anions at longer Cu–N distance of 2.537(2) and 2.600(5)Å, respectively. Both materials are characterized by the presence of weak antiferromagnetic exchange coupling. Despite the one-dimensional (1D) character of the structure, the analysis of magnetic properties and specific heat at very low temperatures shows that [Cu(en)2][Pt(CN)4] behaves as two-dimensional (2D) spatially anisotropic square lattice Heisenberg magnet, while more pronounced influence of interlayer coupling is observed in [Cu(dmen)2][Pt(CN)4]. [Copyright &y& Elsevier]

A novel polymeric one-dimensional compound Cu(tn)Cl2 (tn = 1,3-diaminopropane) was prepared and structurally characterized, and its spectral, magnetic, thermodynamic, and thermal properties were studied. The unique structure shows ladderlike chains composed of CuII atoms and chloro bridging ligands [Cu(-μ3-Cl-)Cu2] running along the crystallographic c axis. The coordination geometry about copper (4 + 2) approximates that of a strongly elongated octahedron. The equatorial plane of the coordination octahedron is formed by a chelate N-bonded tn ligand and two chloro ligands. One of the chloro ligands is terminal, and the other one, μ3-Cl-, forms two additional longer bonds to the neighboring copper atoms and thus occupies the axial octahedral positions. The electronic ground state of the CuII ion is of dz² symmetry and suggests the activation of intraladder and interladder Cl⋯H-N hydrogen bonds as exchange paths that form a two-dimensional pattern of a triangular symmetry. The interaction due to the hydrogen bonds seems to play an important role in molecular packing and magnetic coupling. The studies of magneto-structural correlations including electron paramagnetic resonance measurements and thermodynamic and magnetic properties revealed a two-dimensional character of magnetic correlations with the effective intralayer exchange coupling J/kB ≈ -3 K. No phase transition to the ordered state has been observed down to 60 mK. Cu(tn)Cl2 with the interlayer coupling J ≈ 10-3J and moderate intralayer interaction represents an excellent example of a two-dimensional magnetic system. [ABSTRACT FROM AUTHOR]

Abstract: Magneto-structural correlations in Mn(en)Ni(CN)4 (en = ethylenediamine) (MENC) have been studied. The crystal structure of MENC was refined by Rietveld analysis of X-ray powder diffraction data; it is three-dimensional (3d) and is built up of [Mn(en)]2+ cations with deformed octahedrally coordinated Mn(II) atoms and [Ni(CN)4]2− anions containing square-planarly coordinated Ni(II) atoms. The building species are linked by bridging -cyano ligands. The characterization of magnetic properties confirmed the expected 3d nature of spin correlations by observing λ-like anomaly in specific heat at . The resulting exchange interaction is somewhat smaller than that found in other complexes with the same type of exchange paths. [Copyright &y& Elsevier]

The magneto-structural correlations in Ni(en)2Pd(CN)4 (NEPC) have been studied. The crystal structure is formed by infinite electroneutral 2,2-TT type chains [&z.sbnd;Ni(en)2&z.sbnd;NC&z.sbnd;Pd(CN)2&z.sbnd;CN&z.sbnd;] (en=1,2-diaminoethane) in which the paramagnetic nickel atoms are bridged by diamagnetic tetracyanopalladate anions. Contrary to the previous room temperature X-ray analysis of NEPC, the results of the current structure determinations at both 293 and 150 K showed the nickel atom to be coordinated in the form of slightly elongated octahedron with two chelate bonded and disordered en molecules in the equatorial plane (mean Ni&z.sbnd;N distance of 2.096 A˚ at both temperatures) and N-bonded bridging cyano groups in the axial positions (Ni&z.sbnd;N distances of 2.117 and 2.108 A˚ at 293 and 150 K, respectively). Consequently, the zero field splitting parameter D is finite and positive. The chains are held together by weak hydrogen bonds of the N&z.sbnd;H⋯N(&z.tbnd;C) type. Magnetisation, susceptibility and specific heat measurements indicate that NEPC represents an S=1 Heisenberg magnetic chain characterised by strong planar anisotropy, D/kB&ap;5 K, weak in-plane anisotropy, E/D=0.1, and by a small exchange coupling constant, J/kB&ap;0.25 K. These properties are similar to those exhibited by an analogous compound Ni(en)2Ni(CN)4. [Copyright &y& Elsevier]

The review surveys the preparation methods, crystallochemistry and magnetic properties of one-dimensional cyanocomplexes. Their preparation methods are mainly based on reactions in solutions containing suitable building blocks as precursors of the polymeric structure. The analysis of published data on crystal structures is given, as the knowledge of the crystal structure is essential for the study of magneto-structural correlation. Published data on magnetic properties are discussed along with the methods used for the study of magnetic properties. [Copyright &y& Elsevier]

Abstract: New radical cation salt of bis(ethylenedithio)tetrathiafulvalenium and iron bis(dicarbollide) [BEDT-TTF]2[3,3′-Fe(1,2-C2B9H11)2] (1) has been synthesized. The crystal structure of 1 has been determined by single-crystal X-ray diffraction method found to be isostructural to the known Co and Cr analogues. The electric conductivity measurement in the range of 110÷296 К shows that 1 is semiconductor with the room temperature conductivity σ293 =1.5×10−2 Ω−1 cm−1, that is higher than in the Cr analogue and lower than in the Co analogue. The measurement of magnetic susceptibility in the range of 2÷300K revealed that 1 is paramagnetic with the absence of significant interactions between the organic radical cations and the paramagnetic anions. [Copyright &y& Elsevier]

Abstract: The polymeric complex, {[Cu(tmen)][Pt(CN)4]} n (tmen =tetramethylethylenediamine) has been synthesized and characterized by elemental analysis, infrared spectroscopy, single-crystal structure analysis and by measurement of magnetic properties. Four ν(C N) absorption bands have been recorded in the infrared spectrum of this compound, what corresponds with four different types of cyano groups in the structure. Crystal structure revealed that one cyano group is terminal whereas three crystallographically different cyano groups of [Pt(CN)4]2− anions bridge Pt(II) and Cu(II) atoms to form a two-dimensional structure with a weak antiferromagnetic exchange coupling. [Copyright &y& Elsevier]

[Ni(fum)(phen)] (fum = fumarato, phen = 1,10 -phenanthroline) has been identified as a system consisting of antiferromagnetic S = 1 dimers with single-ion magnetic anisotropy D comparable to the intradimer exchange coupling J , D / J ≈ 1 and D / k B = −6 K. We present reclassification of the physical model of [Ni(fum)(phen)] magnetic subsystem and the magnetocaloric investigation of a [Ni(fum)(phen)] powder sample at temperatures above 2 K in magnetic fields up to 7 T. The analysis of magnetic specific heat and magnetocaloric effect in [Ni(fum)(phen)] has shown that the temperature dependence of the isothermal entropy change under different magnetic fields is in good agreement with theoretical predictions for the S = 1 ferromagnetic dimer with D / k B = −11.5 K, E / k B = −3.4 K and intradimer exchange coupling J / k B = 2.5 K. Sizeable conventional magnetocaloric effect was found around 5.8 K leading to - ΔS max = 8.2 Jkg−1K−1 for ΔB = 7 T. • Magnetocaloric effect in [Ni(fum)(phen)] – ferromagnetic dimer. • The maximal entropy change –Δ SM ≈ 8.2 J/(Kkg) is achieved in 7 T. • The intradimer ferromagnetic coupling improves the magnetocaloric properties. [ABSTRACT FROM AUTHOR]