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This paper presents the structural and optoelectronic behavior of ZnSiP2 compound theoretically. The calculations are performed using full potential linearized augmented plane wave method (FP-LAPW) within density functional theory (DFT) as embodied in WIEN2K code. For the accuracy of calculation, Perdew-Burke generalized gradient approximation (PBE-GGA) is used. Based on the energy bands, the forbidden band gap of ZnSiP2 was found to be 1.37 eV which is suitable for photovoltaic applications. The formation of bands are explained with the help of spectra of density of states (DOS) to determine the effect of Ge doping at Si site on the electronic structure. We have also performed the computations for ZnSi0.875Ge0.125P2. Energy dependent absorption spectra is also reported in this paper to highlight the possible utilization of these compounds in optoelectronic devices.

Co2FeAl Heusler alloy was selected as a target to study L21 and XA ordering of atoms by first-principles calculations using WIEN2k code. It has been observed that Co2FeAl (CFA) Alloy tend to form L21 type structure,which is more energetically favorable and much stable compared to XA type structure. Further, we observed that the total magnetic moment (Mt) shows a strong dependence on site preferences of Fe in all available Wyckoff sites. However, this compound does not show a half-metallic character in both types of ordered structures still, it can be used as the spin-polarized material for spintronics application. Our results are opposite to usual site preference rule and approving the validity of the Slater-Pauling rule.

For acquiring a reasonable description of the structural, electronic, optical of CdSiAs2 pnictide semiconductor and its surface structure in (100) and (001) growth direction, first principle calculations have been computed by DFT implemented in WIEN2k. PBE- sol exchange correlation functions along with a more advanced technique namely, modified Becke Johnson exchange potential (mBJ-GGA) have been used for the calculations since mBJ gives results closer to the experimental value of band gap. Lattice constant, band gap and density of states (DOS) have been calculated. Bulk CdSiAs2 exhibits a direct band gap of 1.46 eV and major contribution to the density of states is from the Cd-d states while the surface structures of CdSiAs2 with 10 A thickness evidence metallic nature. While the reflectivities of both surfaces and bulk are optimal from UV to IR range, optical properties of bulk chalcopyrite CdSiAs2, computed in terms of dielectric constant, absorption coefficient, reflectivity and refractive index, show that absorption is high in ultraviolet and visible regions of energy spectrum thereby making it suitable for photonic and optical applications.

The chromium based fully compensated ferrimagnet, Cr2CoAl has been earlier proposed to show half-metallic ferromagnetism. In this paper, we thoroughly study the effect of atomic disorders on spin polarization, half-metallic character and magnetism in Cr2CoAl using Full-Potential Linearized Augmented Plane Wave method as implemented in WIEN2k code. Cr2CoAl exists in Inverse Heusler alloy structure with space group F4¯3m (No. 216). This study includes five types of disorders namely A2a-, A2b-, DO3a-, DO3b- and B2-type (as suggested by Singh et al for Inverse Heusler alloy). Our calculations predict Cr2CoAl as near half-metallic ferromagnet with 97% spin polarization. A2a-, A2b- and DO3a-type disorders exhibit high spin polarization of 98%, 99%, and 81%, respectively, whereas DO3b-and B2- type disorder exhibit 61% and 70% spin polarization, respectively. The energetics of these disorders suggest that DO3a-type disorder is more probable to occur but the high spin polarization in spite of disorder favors its application in spintronics devices. The total spin magnetic moment of Cr2CoAl is 0 µB, which increases with the disorders.

TheFull-potential linearized augmented plane wave method in WIEN2k was used to calculate electronic and magnetic properties of Fe2NiMn and Electronic properties of Fe2NiCo. The lattice constant were calculated to be 5.8 A for Fe2NiMn as well as for Fe2NiCo. The electron density calculated is not completely spherical which indicates the presence of half-metallic nature of the alloy in majority and minority spin of Fe2NiMn and Fe2NiCo. The magnetic moment were also analyzed.

In this report, La2-xSrxCoMnO6 (x=0, 1) have been synthesised using sol-gel technique. La2CoMnO6 (LCMO) takes a monoclinic phase, whereas LaSrCoMnO6 (LSCMO) appears in a mixed phase of having both monoclinic and rhombohedral symmetries. DC magnetization measurement shows that LCMO is Ferromagnetic in nature whereas LSCMO shows magnetic glassy nature. This experimental result is verified by ab-initio calculation using GGA+SO+U as implemented in WIEN2k code. Total energy calculations suggest that antisite disorder is enhanced with Sr doping at La site and LSCMO is predominantly ferromagnetic in nature. Co ions which appeared in high spin +2 charge state, converts to intermediate spin +3 charge state with Sr doping.

The calculation is carried out using the FPLAPW method in the DFT framework within mBJ and LDA using the WIEN2k code. The investigation of electronic properties showed Ba2VMoO6 to be semi-metal in spin-up and insulation in spin down. In both spin up and spin down channel, direct band gap along with indirect band gap in ΓX direction was observed. For investigation of the optical transitions in this compound, the real and imaginary parts of the dielectric function, reflectivity, refractive index and optical conductivity of real and imaginary parts are calculated and analysed.

Cr2TeO6 and Fe2TeO6 crystallize in tetragonal structure. These compounds are formed in nuclear reactors. Therefore, study of thermal expansion of these compounds is important. In this paper, using WIEN2k code we have calculated the volume dependent total energies E(V) of these materials at zero kelvin. Subsequently, we have applied the quasi harmonic approximation, in order to include the thermal effects. Using our calculations, we have predicted the thermal expansion and specific heat at high temperatures. The calculated properties for Fe2TeO6 are in very good agreement with the reported experimental results.

The density of states (DOS) and the magnetic moments of PrFeO3 and NdFeO3 have been studied by first principles full-potential linearized augmented plane wave (FP-LAPW) method based on density functional theory (DFT). For the exchange correlation potential, the generalized gradient approximation (GGA) has been used. The calculated structural parameters are consistent with the experimental results. Total and partial DOS have been computed using the WIEN2k code. The strong hybridization of the O-2p, Fe-3d and Pr/Nd-4f states around the Fermi level reveals that these compounds are metallic. The effective magnetic moment of PrFeO3 is found to be 4.81 µB while for NdFeO3 it is 5.95 µB. It is found that the origin of magnetism in these compounds is double-exchange-interaction between Fe-3d states via O-2p states (Fe-O-Fe).

In this work, we present the electronic and optical properties of Cu3SbSe3 calculated under the purview of Density Functional Theory. For the first time, optical properties including dielectric function, refractive index, optical conductivity, reflectivity and absorption coefficient were calculated by a self-consistent approach using the WIEN2k code. mBJ exchange potential was used for the calculation of band structure.

Electronic structure and magnetic properties of Ti2MnSb Heusler alloy were computed using density functional theory implemented in WIEN2k code. The calculated magnetic moment at equilibrium lattice constant 6.33A was 2μB. Ti2MnSb shows a half metallic ferrimagnetic behavior with 0.77eV gap in the minority spin.

First principle study of the electronic band structure of Ba2DySbO6 synthesied by the solid state reaction technique have been performed within the framework of density function theory using WIEN2K. It has been shown in the absence of electron-electron interaction (U=0), BaDySO6 behaves like a half-metal. Even in the presence of DFT+U, electron-electron interaction via the Hubbard term (from U = 0, 2.72e -7.02eV), it still shows half metals.

The electronic and magnetic properties of Ni-doped CeO2 diluted amgentic semiconductor (DMS) including the effect of oxygen vacancy (Vo) with doping concentration, x = 0.125 have been calculated using FPLAPW method based on Density Functional Theory (DFT) as implemented in WIEN2k. In the present supercell approach, the XC potential was constructed using GGA+U formalism in which Coulomb correction is applied to standard GGA functional within the parameterization of Perdew-Burke-Ernzerhof (PBE). We have found that the ground state properties of bulk CeO2 compound have been modified significantly due to the substitution of Ni-dopant at the cation (Ce) site with/without VO and realized that the ferromagnetism in CeO2 remarkably depends on the Vo concentrations. The presence of Vo, in Ni-doped CeO2, can leads to strong ferromagnetic coupling between the nearest neighboring Ni-ions and induces a HMF in this compound. Such ferromagnetic exchange coupling is mainly attributed to spin splitting of Ni-d states, via electrons trapped in Vo. The HMF characteristics of Ni-doped CeO2 including Vo makes it an ideal material for spintronic devices.

The electronic and magnetic properties of pristine and Cr doped graphene have been calculated using WIEN2k implementation of full potential linearized augmented plane wave (FPLAPW) method based on Density Functional Theory (DFT). The exchange and correlation (XC) effects were taken into account by generalized gradient approximation (GGA). The calculated results show that Cr doping introduces appropriate magnetic moment on graphene. The p-d interaction between 3d states of Cr atom and p-states of C atom are responsible for half metallicity in graphene. The calculated Half-metallic behavior of Cr-doped graphene makes it an ideal candidate for spintronic applications.

The structural, electronic, bonding and optical properties of cubic perovskite LaGaO3 have been calculated using the full-potential linearized augmented plane wave (FP-LAPW) method in the density functional theory (DFT) as embodied in WIEN2k code. The modified Becke-Johnson (mBJ) potential is applied for the calculation of electronic and optical properties. The calculated lattice constant is in good agreement with the experimental result. The predicted band structure shows an indirect (M-X) band gap of 4.22 eV. The bonding in the material is of mixed covalent and ionic nature. Optical properties like dielectric function, refractive index, reflectivity, conductivity and absorption coefficient are presented.

The structural phase transition properties of lutetium nitride (LuN) under high pressure have been investigated using full potential linear augmented plane wave plus local orbitals approach within the framework of density functional theory as implanted in the WIEN2k package. Generalized gradient approximation (GGA) is chosen for solving exchangecorrelation functional. The total energy has been optimized as a function of the unit cell volume in different phases. The equilibrium parameters like lattice constants (a), bulk modulus (B0) and its pressure derivative (B0’) and total energy (E0) are calculated and compared with earlier reported theoretical and experimental data. The calculated parameters are in good agreement with earlier reported experimental as well as theoretical results.

The structural, electronic and elastic properties of YN have been investigated under high pressure. All calculations have been carried out using FP-LAPW method within the framework of self consistent density functional theory. The generalized gradient approximations based on exchange-correlation energy optimization have been used for calculating the total energy using WIEN2K code. At ambient conditions, YN stabilizes in six-fold rock-salt (B1) structure which further transforms to eight-fold cesium chloride (B2) structure. The equilibrium lattice constant (a0), bulk modulus (B0) and its first-order pressure derivative (B’0) agree well with the available experimental data. The phase transition (B1⇥B2) pressure has been computed to be 130.23 GPa. The values of elastic constants have also found close to the other theoretical results. The attempt has also been made for computation and analysis of structural electronic properties for Fe doped YN alloy in both ambient as well as high pressure phase. The calcula...

Recent technological developments have lead to increasing demands for the materials with special properties. Nitrogen-containing compound semi-conductors are key materials for compact, high-efficiency light sources for this century. One of those is Indium nitride (InN). It is emerging as a "hot" material for potential application in nitride based high power, high frequency transistor devices because of its high mobility. In the present paper, we focus on the role played by d-electrons on the electronic structure of zinc blende modification of indium nitride. The In 4d electrons are treated both as core and as valence electrons. The calculations are performed using the FP-LAPW approach plus local orbitals, within the framework of density functional theory (DFT) as implemented in the Wien2k code.

First principles calculations for structural and electronic properties of GaAs have been reported using a full potential linearized augmented plane wave (FP-LAPW) scheme of calculations developed within density functional theory (DFT). We use in this study local density approximation (LDA), Perdew-Burke-Ernzerhof parameterized generalized gradient approximation (PBE-GGA), Wu-Cohen parameterized GGA (WC-GGA) executed in WIEN2k code. In addition, to calculate band structure with high accuracy we used modified Becke-Johnson exchange potential (MBJ) + LDA approach. Our calculated lattice constant with GGA-WC is in good agreement to experimental value than LDA and PBE-GGA. Whereas our calculations for the band structure show that MBJ+ LDA approach gives much better results for band gap value as compared to other exchange correlation approaches.

The electronic, structural, mechanical and thermal properties of strongly correlated HoSb in the stable Fm3m and high‐pressure Pm3m phases have been analyzed using full‐potential method at normal and high pressures. The spin polarized Local Spin Density Approximation (LSDA) based on exchange‐correlation energy optimization has been used for calculating the total energy using WIEN2K code. The structural properties viz., equilibrium lattice constant, bulk modulus and its pressure derivative agree well with the available experimental data. The electronic structures have been obtained with the LSDA and LSDA+U approach. The LSDA+U strategy shows significant impact on the energy levels of the occupied and unoccupied 4f states of HoSb.

The pressure induced structural phase transformation and elastic properties of LaAs have been studied using WIEN2k code. The calculations are performed with generalized gradient approximation (GGA) and local density approximation (LDA). The calculated structural and elastic properties viz., equilibrium lattice constant, bulk modulus and its pressure derivative agree well with the experimental data.

The structural and electronic properties of CdO in NaCl (B1) and CsCl (B2) structure are examined with first principle. All calculations have been carried out with the plane wave pseudo‐potential in the frame of self consistent density functional theory method. Here local density approximations based on exchange‐correlation energy optimization have been used for calculating the total energy using WIEN2K code. CdO shows structural phase transformation from B1 to B2 at 89.7 GPa which is very close to experimental result. The structural properties (equilibrium lattice constant, bulk modulus, pressure derivative of bulk modulus) of CdO are also calculated at ground state and high pressure is also calculated.

In this wok, we present the density functional theory (DFT) calculations of cubic III‐N based semiconductors by using the full potential linear augmented plane‐wave method plus local orbitals as implemented in the WIEN2k code. Our aim is to predict the pressure effect on structural and electronic properties of III‐N binaries and ternaries. Results are given for structural properties (e.g., lattice constant, elastic constants, bulk modulus, and its pressure derivative) and electronic properties (e.g., band structure, density of states, band gaps and band widths) of GaAs, GaN, AlN, and InN binaries and GaAsN ternaries. The proposed model uses GGA exchange‐correlation potential to determine band gaps of semiconductors at Γ, L and X high symmetry points of Brillouin zone. The results are found in good agreement with available experimental data for structural and electronic properties of these semiconductors.

An experimental and theoretical study of the K absorption pre‐edge in hematite (α‐Fe2O3) is presented. Resonant inelastic X‐ray scattering with a 3p hole in the final states was used to obtain spin‐selective absorption spectra. Spectral variations with changing the orientation of the incident X‐ray polarization vector with respect to the crystal c‐axis in single crystalline hematite are discussed. The experimental results can be successfully modeled using a band‐structure approach (WIEN2k with LDA+U). A pre‐edge absorption feature is assigned to unoccupied p electronic states due to Fe‐Fe interactions, i.e. they are due to non‐local transitions.

We present a first‐principles calculation of the density of states(DOS), electronic band structure and magnetic moment of SmCo4B. The magnetic properties of SmCo4B using density functional theory(DFT) calculations are treated beyond the local density approximation (LDA) within the LDA+U scheme as implemented in the wien2k package. The calculated magnetic moment is in fair agreement with available experimental values. The features of both DOS and band structure depend on the scheme used in the calculation. The results are discussed and compared to those of SmCo5.