A density functional theory (DFT) employing generalized gradient approximation (GGA) has been used to study the electronic and magnetic properties of Mo doped SnO2. The presence of symmetric density of states (DOS) and direct band gap in Sn1-xMoxO2 (at x = 0.00) predicts this material to be a direct band gap semiconductor. The substitution of Mo atoms on the Sn sites induced a spin functionality on the DOS. The Mo impurities played an important role in facilitating the hybridization between Mo-d and O-p orbitals. The p - d hybridization gives an antisymmetric DOS at the E-F by creating spin splitting at Mo-d states. The higher value of energy spin splitting is responsible for the partial magnetic moment at Mo site. In all composition except at x = 0.0, wide band gaps are preserved at the spin down region and a metallic characteristic at the spin up region, confirm its metal-semiconductor hybrid property. These type of materials exhibit 100% spin polarization at the E-F, which can be a potential candidate for electron-spin based futuristic devices.

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 l 'X 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.

In this study, first-principles investigations were performed using the full-potential linearized augmented plane-wave method of the structural and optoelectronic properties of thorium germinate (ThGeO4), a high-K dielectric material. Under ambient conditions, the structural properties calculated for ThGeO4 in the zircon phase were in excellent agreement with the available experimental data. Furthermore, using the modified Becke-Johnson correction method, the calculated band gaps and optical constants accurately described this compound. Finally, the thermal properties were predicted over a temperature range of 0700 K and pressures up to 11 GPa using the quasi-harmonic Debye model, where the variations in the heat capacity, primitive cell volume, and thermal expansion coefficients were determined successfully.

The electronic and magnetic properties of Fe atomic wire and atomic plane have been theoretically investigated from full potential linearized augmented plane wave (FPLAPW) method within a frame work of density functional theory (DFT). This work is based on the comparative study of number of Fe nanochains with infinite length and infinitely spread Fe nanosheet. A most commonly adopted GGA approximation is used for electron exchange correlation. In our calculation, the property of Fe-chain is predicted to be magnetic metal with the presence of deep valley (in Spin-up DOS) and a peak (in Spin-down DOS) at Fermi level ([Formula: see text]) shows the antisymmetric DOS. The presence of antisymmetric DOS is a signature of exchange splitting between the degenerated d-states. The splitting between t[Formula: see text] states is very prominent in Fe-chain which enhances the magnetic moment. The magnetic moment decreases with the increase in number of Fe-chains.

The structural, electronic and optical properties of the cubic RbMF3 perovskites (M = Be, Mg, Ca, Sr, Ba) have been investigated using the full -potential linearized augmented plane wave (FP-LAPW) method. The exchange and correlation potential was applied using the generalized gradient approximation for calculating the structural properties In addition, the modified Becke-Johnson (TB-mBJ) potential was used for calculating the electronic and optical properties. It was found that the lattice constant increases while the bulk modulus decreases with the change of cation (M) in going from Be to Ba in the RbMF3 perovskites (M = Be, Mg, Ca, Sr, Ba). The reflectivity and absorption properties were also studied using the mBJ method to understand the inter -band transitions and their possible applications in absorption devices in the UV-region. (C) 2017 Elsevier B.V. All rights reserved.

We have performed the density functional theory based calculation to study the electronic and thermoelectric properties of BaFe4−xRuxAs12 (x = 0%, 25%, 50%, 75%, and 100%) within the framework of the full potential-linearized augmented plane wave method. The composite alloys are found to be stable in their optimized crystal structures and their lattice constants are in close agreement with the corresponding experimental reports. The structural stability and mechanical properties are also studied using their elastic constants. The hardness of these materials increases with increasing concentration of Ru, which also donates the covalent nature of inter-atomic bonding of BaRu4As12. The analysis of energy bands and density of states reflects the semi-metallic nature of BaFe4As12 and BaRu4As12, whereas other doped materials show metallic character. The electronic structure calculation suggests the high Seebeck coefficient with the efficient thermoelectric application of these materials. The thermal transport investigation also supports the result obtained from the electronic structure calculation. The thermoelectric efficiency defined by the figure of merit (ZT) of pure BaFe4As12 (ZT = 0.004) and BaRu4As12 (ZT = 0.005) has been enhanced to 0.357 with 75% Ru doping. The spin-polarized calculation shows a significant effect on their energy band structure, giving magnetic behavior of the sample materials. The analysis of their magnetic profile suggests the ferromagnetic nature of these materials, except BaRu4As12, which shows a paramagnetic ground state.

We have performed the FP-LAPW calculation based on the density functional theory (DFT) to study the electronic and magnetic properties of binary compounds MC (M = Be, Mg, Ca, Sr, Ba and Ra). The density of states (DOS) and band structures were studied to understand the electronic properties. We have employed an orbital independent semilocal exchange potential called modified Becke Johnson (mBJ) which includes a large proportion of electrons residing in the intestinal regions. Thus the information obtained from mBJ is more accurate as compared to conventional DFTs (GGA/LDA) as their potential is electron orbital dependent. Among the systems under our investigation CaC, SrC, BaC and RaC has given the 100% spin polarization at Fermi energy (E-F) within GGA whereas mBJ open a gap for all the systems. The total magnetic moment was found to be 2.00 u(B) which is an integer value as expected for the HMF systems. The large half metallic gaps and location of E-F was found to be robust with respect to lattice constants in RaC and BeC.

We have investigated the semiconducting and piezoelectric properties of bulk MNiSn (M=Ti, Zr, Hf) type a half-Heusler compound with cubic F-43m symmetry by means of density functional theory (DFT). For electron exchange correlation a generalized gradient approximation (GGA) was used. Special attention was paid to establish a most favourble ground state configuration on magnetic as well as non-magnetic ordering. With fully optimized structure the electronic and ferroelectric calculation was performed. The formation of band gap was discussed on the basis of d-d orbital hybridization. Further we have calculated the spontaneous polarization by means of structural deformation.

Though PrInO3 is structurally anisotropic it is found to be optically isotropic which is the basic requirement for ceramic scintillators.

Density functional theory-based calculations of the elastic and electronic properties with magnetic moments of the filled skutterudite (mathrm{EuRu}_{4}mathrm{As}_{12}) have been performed in its ferromagnetic ground state. The full-potential linearized augmented plane wave (FP-LAPW) method has been used for the study presented here. The numerical values of the elastic parameters are estimated within the framework of the Voigt–Reuss–Hill approximations. The energy band structure calculation performed near the Fermi energy level shows the metallic nature of the material with a high value of Seebeck coefficient (S). The presence of an exchange splitting of Eu-4f states suggests their appreciable contribution toward the magnetic behavior. The analysis of the thermal transport properties confirms the result obtained from the electronic structure calculation with Seebeck coefficient of (118,,upmu hbox {V/K}) and the figure of merit (ZT) value of 0.51, at room temperature. The estimated values of S and ZT indicate the possibility of the thermoelectric applications of the sample material.

The electronic and optical properties of cubic SrHfO3 under the variation of pressures were investigated by first-principles calculation within the framework of generalized gradient approximation (GGA). The calculated equilibrium lattice constant of cubic SrHfO3 is in good agreement with available experimental and theoretical results. The result shows that SrHfO3 is an insulator with an indirect band gap up to 20.00 GPa, along (M - Gamma). While the application of pressure above 20.00 GPa the band gap changes to direct band gap, along (Gamma - Gamma). The band gap increases from 3.80 eV to 4.11 eV with the increase in pressure from 0.00 GPa to 35.00 GPa. In order to understand the optical properties of SrHfO3 perovskite, the dielectric function, optical conductivity and electron energy loss are calculated for photon energy up to 14.00 eV. We have also observed the decrease in static dielectric constant with the increase in energy band gap under pressure. (C) 2016 Published by Elsevier B.V.

The density functional theory (DFT)-based fully relativistic version of the full-potential linearized augmented plane wave method with spin–orbit coupling (SOC) has been used to study the electronic and optical properties of the filled skutterudite \(\hbox {CeRu}_{4}\hbox {As}_{12}\). The exchange and correlation potential has been treated with the local density approximation (LDA). The analysis of the density of states and energy bands in the vicinity of the Fermi energy level suggests the semiconducting nature of the material with narrow indirect energy band gap of 0.11 eV; however, the gap value increases to 0.17 eV for without SOC calculation. Additionally, the modified Becke–Johnson (mBJ) potential has been utilized along with the LDA approach to estimate the precise value of the energy band gap of the material. The mBJ treatment enhances the energy band gap to −0.2 eV. In order to understand the structural and mechanical properties of the sample material, the elastic constants are also estimated at ambient conditions. The analysis of the elastic constants suggests the brittle nature of the material whose stiffness is comparable with that of \(\hbox {CeOs}_{4}\hbox {Sb}_{12}\) and the covalent contribution is expected in the bonding. The optical response of the material has been studied from the energy bands, which reflects the metallic behavior of the material in the infrared region of frequency radiation and turns to act as opaque material with superluminal behavior at ultraviolet frequency radiation. The inclusion of the hybrid functional in the calculation suggests the metallic nature of the material.

The structural, electronic and magnetic properties of Nd-doped Rare earth aluminate, La1−xNdxAlO3 (x=0–100%) are studied using the full potential linearized augmented plane-wave (FP-LAPW) method within the density functional theory. The effects of Nd substitution in LaAlO3 are studied using super-cell calculations. The electronic structures were computed using modified Beck Johnson (mBJ) potential based approximation with the inclusion of Coulomb energy (U) for Nd-4f state electrons. The La1−xNdxAlO3 may possess half metallic behavior on Nd doping with finite density of states at EF. The direct and indirect band gaps were studied as a function of Nd concentration in LaAlO3. The calculated magnetic moments in La1−xNdxAlO3 were found to arise mainly from the Nd-4f state electrons. A probable half-metallic nature is suggested for these systems with supportive integral magnetic moments and high spin polarized electronic structures in these doped cases at EF. The controlled decrease in band gap with increase in concentration of Nd doping is a suitable technique for harnessing useful spintronic and magnetic devices.

The electronic and magnetic properties of Heusler compounds X(2)YZ and XYZ (X = Co, Ni, Pt, Fe; Y = Mn, Cr, Vi; Z = Al, Sb, Ga) are investigated by using the density functional theory with generalized gradient approximation (GGA), GGA plus U(LSDA+U), and modified Becke-Johnson (mBJ) exchange potential. It is found that the half-metallic gaps are generally widened reasonably by LSDA+U and mBJ as compared to the conventional GGA. For the Co-based Heusler compounds the inclusion of U in GGA leads to a larger minority band gap while it is destroyed for Fe2VAl and NiMnSb. The magnetic properties of Co2VSi and Co2VSn are well defined within LSDA+U and mBJ with an exact integer value of magnetic moment. The band gaps of Fe2VAl and CoMnSb given by mBJ are in good agreement with the available experimental data of x-ray absorption spectroscopy. Except for the reasonably larger band gap, the mBJ band structure is almost same as that of GGA but is remarkably different from that of LSDA+U.

The energy band structure and the optical response of the filled skutterudite CeRu4As12 have been studied using the full-potential linearized augmented plane wave (FP-LAPW) method within the local density approximation (LDA). The analysis of the region close to the Fermi energy level suggests the narrow band gap (0.18eV) semiconducting nature of the material. The new approach of the exchange-correlation functional called the modified Becke Johnson potential used in the treatment of the material gives an enhanced band gap value of ~0.2eV. The elastic parameters are also estimated at the ambient condition, which indicates the brittle nature of the studied material. The study of the optical spectra suggests the metallic behavior of the material in the far infrared region, which indicates that it acts as an opaque material with superluminal behavior in the ultraviolet frequency.

Samarium doping effects on the thermoelectric properties in Eu1-xSmxAlO3 (x=0%, 50%, and 100%) were studied using first principles calculations based thermal transport property measurement. The result indicate that the compound is an intrinsic n-type material. Samarium doping has a positive effect on the overall thermoelectric performance of the Eu1-xSmxAlO3 system, with sharp increase in figure of merit (ZT) observed when x=0, 50 and 100% up to 150K. Compared to x=0 and 100%, the case of x=50% was found to have more positive increment in ZT value suggesting that the doing to have positive effect on figure of merit in Eu1-xSmxAlO3. Furthermore, all the samples show stable thermoelectric compatibility factors over a broad temperature range from 700 to 1000 K, which could have great benefits for their practical applications. It is concluded that the overall thermoelectric performance of the Eu1-xSmxAlO3 could be highly enhanced using doping techniques.

The structural, electronic, and magnetic properties of the Nd-doped Rare earth aluminate, La1−xNdxAlO3 (x = 0% to 100%) alloys are studied using the full potential linearized augmented plane wave (FP-LAPW) method within the density functional theory. The effects of the Nd substitution in LaAlO3 are studied using the supercell calculations. The computed electronic structure with the modified Becke–Johnson (mBJ) potential based approximation indicates that the La1−xNdxAlO3 alloys may possess half-metallic (HM) behaviors when doped with Nd of a finite density of states at the Fermi level (EF). The direct and indirect band gaps are studied each as a function of x which is the concentration of Nd-doped LaAlO3. The calculated magnetic moments in the La1−xNdxAlO3 alloys are found to arise mainly from the Nd-4f state. A probable half-metallic nature is suggested for each of these systems with supportive integral magnetic moments and highly spin-polarized electronic structures in these doped systems at EF. The observed decrease of the band gap with the increase in the concentration of Nd doping in LaAlO3 is a suitable technique for harnessing useful spintronic and magnetic devices.

A density functional theory (DFT) approach employing generalized gradient approximation (GGA) and the modified Becke Johnson (TB-mBJ) potential has been used to study the electronic and thermoelectric (TE) properties of ZrxHf1−x−yTayNiSn.