Ab Initio Study of Pressure Induced Structural, Magnetic and Electronic Properties in Plutonium Pnictides

2014 ◽  
Vol 1047 ◽  
pp. 11-17 ◽  
Author(s):  
Chandrabhan Makode ◽  
Jagdeesh Pataiya ◽  
M. Aynyas ◽  
Sankar P. Sanyal
Keyword(s):  
Bulk Modulus ◽  
Total Energy ◽  
Electronic Properties ◽  
Ambient Pressure ◽  
Structural Phase ◽  
Tight Binding ◽  
Energy Band Diagram ◽  
Lattice Parameter ◽  
Local Spin Density Approximation ◽  
Type B

We have investigated the pressure induced structural and electronic properties of plutonium pnictides (PuY, Y= P, As, Sb). The total energy as a function of volume is obtained by means of self-consistent tight binding linear muffin-in-orbital (TB-LMTO) method within the local spin density approximation (LSDA). From present study with the help of total energy calculations (spin polarized) it is found that PuP, PuAs and PuSb are stable in NaCl – type structure under ambient pressure. The structural stability of PuP, PuAs and PuSb changes under the application of pressure. We predict a structural phase transition from NaCl-type (B1-phase) to CsCl-type (B2-phase) structure for these Pu-pnictides in the pressure range of 20.8 – 42.0 GPa. We also calculate the lattice parameter, bulk modulus, band structure and density of states. From energy band diagram it is observed that all the three compounds exhibit metallic behaviour. The calculated equilibrium lattice parameters and bulk modulus are in good agreement with available experimental data.

Pressure Induced Structural and Electronic Properties of Thulium Nitride

2014 ◽  
Vol 1047 ◽  
pp. 147-150
Author(s):  
Yeshvir Singh Panwar ◽  
Mahendra Aynyas ◽  
M.K. Tejraj ◽  
S.P. Sanyal
Keyword(s):  
Phase Transition ◽  
Bulk Modulus ◽  
Electronic Properties ◽  
Structural Phase Transition ◽  
Phase Structure ◽  
Local Density ◽  
Ambient Pressure ◽  
Structural Phase ◽  
Lattice Parameter ◽  
Type B

We report ab initio calculations of pressure induced structural phase transition and electronic properties of thulium nitride (TmN). The total energy as a function of volume is obtained by using the self-consistent tight binding linear muffin-tin-orbital (TB-LMTO) method within the local density approximation (LDA). It is found that TmN is stable in NaCl – type structure under ambient pressure. We predict a structural phase transition from NaCl-type (B1-phase) structure to CsCl-type (B2-phase) structure of this compound at a high pressure of 68 GPa. We also calculate the lattice parameter (a0), bulk modulus (B0), band structure and density of states. From energy band diagram it is observed that TmN exhibit metallic behaviour. The calculated values of equilibrium lattice parameter and bulk modulus are in general good agreement with available experimental data.

Ab Initio Study of Structural Phase Transition and Electronic Properties in Samarium (Sm) Compounds

2016 ◽  
Vol 1141 ◽  
pp. 184-189
Author(s):  
Yeshvir Singh Panwar ◽  
Mahendra Aynyas ◽  
Jagdeesh Pataiya ◽  
Sankar P. Sanyal
Keyword(s):  
Phase Transition ◽  
Bulk Modulus ◽  
Structural Phase Transition ◽  
Local Density ◽  
Structural Phase ◽  
Tight Binding ◽  
Energy Band Diagram ◽  
Lattice Parameter ◽  
Type B ◽  
Lmto Method

The electronic structure and high pressure structural phase transition of SmTe and SmPo have been studied by using tight binding linear muffin-tin-orbital (TB-LMTO) method within the local density approximation (LDA). The total energy as a function of volume is obtained and it is found that these compounds are stable in NaCl-type (B1-phase) structure and transform to CsCl-type (B2-type) structure. The transition pressure of SmTe and SmPo are found to be 6.6 GPa and 8.6 GPa respectively. We have also calculated lattice parameter (a0), bulk modulus (B0), band structure (BS) and density of states (DOS). From energy band diagram, we observed that these compounds exhibit weakly metallic behaviour. The calculated values of lattice parameter and bulk modulus agree well with the available data.

First Principle Calculations of Pressure Induced Structural and Electronic Properties in Americium Monochalcogenides

2014 ◽  
Vol 1047 ◽  
pp. 35-40 ◽  
Author(s):  
Jagdeesh Pataiya ◽  
Mahendra Aynyas ◽  
Chandrabhan Makode ◽  
Archana Singh ◽  
Sankar P. Sanyal
Keyword(s):  
Bulk Modulus ◽  
Energy Band ◽  
Phase Structure ◽  
Local Density ◽  
Ambient Pressure ◽  
Structural Phase ◽  
Tight Binding ◽  
Theoretical Data ◽  
Lattice Parameters ◽  
Type B

The tight-binding linear muffin-tin orbital (TB-LMTO) with in the local density approximation is used to calculate total energy, lattice parameters, bulk modulus, density of states and energy band structures of americium monochalcogenides at ambient as well as high pressure. It is found that AmX (X=S, Se, Te) compounds are stable in NaCl – type structure under ambient pressure. We predict a structural phase transition from NaCl-type (B1-phase) structure to CsCl-type (B2-phase) structure for these compounds in the pressure range of 26.0 – 15.0 GPa (AmS to AmTe). From energy band diagram it is observed that AmX compounds exhibit metallic behaviour. The calculated ground state properties such as lattice parameters and bulk modulus are in general good agreement with available experimental and theoretical data.

Structural and Electronic Properties of Thulium Compounds

2016 ◽  
Vol 28 ◽  
pp. 59-64
Author(s):  
Yeshvir Singh Panwar ◽  
Mahendra Aynyas ◽  
Jagdeesh Pataiya ◽  
Sankar P. Sanyal
Keyword(s):  
Bulk Modulus ◽  
Local Density ◽  
Structural Phase ◽  
Tight Binding ◽  
Energy Band Diagram ◽  
Lattice Parameter ◽  
Band Diagram ◽  
Cscl Type ◽  
Structural And Electronic Properties ◽  
Lmto Method

The tight binding linear muffin-tin-orbital (TB-LMTO) method within the local density approximation (LDA) is used to study the electronic structure and high pressure behaviour of thulium compounds TmX (X= P, As, S, and Se). We also predict a structural phase transition from NaCl to CsCl-type structure. The transition pressures were found to be 40.0, 31.0, 58.0 and 49.0 GPa, for TmP, TmAs, TmS and TmSe respectively. Apart from this, the lattice parameter (a0), bulk modulus (B0), band structure and density of states are calculated. From energy band diagram, it is observed that these compounds exhibit weak metallic character. The calculated values of lattice parameters and bulk modulus are of reasonable agreement with available data.

Ab Initio Investigation of Structural and Electronic Properties of ErPb3 in AB3 Structure

2016 ◽  
Vol 28 ◽  
pp. 39-42 ◽  
Author(s):  
Shubha Dubey ◽  
Gitanjali Pagare ◽  
Ekta Jain ◽  
Sankar P. Sanyal
Keyword(s):  
Bulk Modulus ◽  
Total Energy ◽  
Electronic Properties ◽  
Density Of States ◽  
Experimental Results ◽  
Energy Calculation ◽  
Present Calculation ◽  
Full Potential ◽  
Local Spin Density Approximation ◽  
Calculated Density

The structural properties and electronic properties of the intermetallic compound ErPb3 which crystallize in AuCu3 type structure (AB3) are studied by means of first principles total energy calculation using full potential linearized plane wave method (FP-LAPW) within the generalized gradient approximation of Perdew, Burke and Ernzrhof (PBE) and local spin density approximation (LSDA) for the exchange correlation functional and including spin magnetic calculation. The total energy is computed as a function of volume and fitted to the Birch-Murnaghan equation of state. The ground state properties of this compound such as equilibrium lattice parameter (a0), bulk modulus (B), and its pressure derivative (B’) are calculated and compared with the available experimental results. We find good agreement with the other theoretical and experimental results. For the compounds, the values of lattice constants obtained by PBE-GGA overestimates and by LSDA underestimates the available experimental values for the same, which verifies the reliability of the present calculation. The value obtained for the bulk modulus is 50.63 GPa. The analysis of electronic properties is achieved by the calculation of the band structures and the density of states in both the spin up and spin down modes, which show a metallic character of ErPB3 due to zero band gap. The values of calculated density of states are found to be 0.36 eV/states and 11.46 eV/states in spin-up and spin-down mode respectively. The calculated magnetic moment (μm) of ErPb3 is 2.06.

Structural and Electronic Properties of Neptunium Sulphide: An Ab Initio Study

2016 ◽  
Vol 28 ◽  
pp. 23-26
Author(s):  
Chandrabhan Makode ◽  
Mahendra Aynyas ◽  
Jagdeesh Pataiya ◽  
Sankar P. Sanyal
Keyword(s):  
Phase Transition ◽  
Electronic Properties ◽  
Density Functional ◽  
Ambient Pressure ◽  
Energy Band Diagram ◽  
Lattice Parameter ◽  
Generalized Gradient ◽  
Transition Pressure ◽  
Phase Transition Pressure ◽  
Structural And Electronic Properties

The density functional theory within generalized gradient approximation (GGA) has been used to calculate lattice parameter, total energy, phase transition pressure and electronic properties of neptunium sulphide (NpS). From our calculations we observe that NpS is stable in NaCl – type structure under ambient pressure. For this compound, the phase transition pressure was found to be 29.5 GPa. The nature of metallic behaviour is remarked from energy band diagram in NpS. All properties obtained for this compound are in good agreement with available results.

Ground State and Electronic Properties of Americium (Am) Compounds

2016 ◽  
Vol 1141 ◽  
pp. 176-179
Author(s):  
Jagdeesh Pataiya ◽  
Mahendra Aynyas ◽  
Chandrabhan Makode ◽  
Sankar P. Sanyal
Keyword(s):  
Electronic Properties ◽  
Ground State ◽  
Local Density ◽  
Ambient Pressure ◽  
Structural Phase ◽  
Tight Binding ◽  
Type Structure ◽  
Cscl Type ◽  
Lmto Method ◽  
First Time

The ground state and electronic properties of americium pnictides (AmY, Y=N, P) has been calculated with the help of tight binding linear muffin-in-orbital (TB-LMTO) method within the local density approximation (LDA). From present study it is found that AmN and AmP are stable in NaCl – type structure under ambient pressure. The structural stability of AmN and AmP changes under the application of pressure. We predict a structural phase transition from NaCl-type to CsCl-type structure for these Am-pnictides in the pressure range of 36.0 – 47.0 GPa (AmN-AmP). Optimized lattice parameters, transition pressures and bulk modulus were obtained for the first time and analyzed in comparison with the available theoretical and experimental data.

Structural, elastic, magnetic and electronic properties of TiX2(X = Cr, Mn) alloys

2019 ◽  
Vol 33 (12) ◽  
pp. 1950115
Author(s):  
R. Murugeswari ◽  
A. Milton Franklin Benial ◽  
R. Rajeswarapalanichamy
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Ambient Pressure ◽  
Structural Phase ◽  
Ferromagnetic Materials ◽  
Hexagonal Structure ◽  
First Principles Calculations ◽  
Simulation Code ◽  
Functional Theory ◽  
Lattice Constants

The structural, elastic, magnetic and electronic properties of titanium-based alloys TiX2(X = Cr, Mn) are investigated by the first-principles calculations based on density functional theory using the Vienna ab-initio simulation code. The lattice constants of TiX2(X = Cr, Mn) alloys are optimized for various possible structures such as hexagonal, tetragonal and orthorhombic. TiX2(X = Cr, Mn) alloys are highly stable in hexagonal structure with the space group P63/mmc at ambient pressure. A pressure-induced structural phase transition from hexagonal structure to the tetragonal structure is observed in TiCr2at 443.3 GPa and in TiMn2hexagonal structure to orthorhombic structure is at 295.05 GPa. The electronic structure shows that TiX2(X = Cr, Mn) alloys are metallic in nature at all pressures. The magnetic property of nonmagnetic TiX2(X = Cr, Mn) alloys are analyzed by doping with ferromagnetic materials (Fe, Co and Ni) using the stoichiometries of TiX[Formula: see text]Y[Formula: see text] (X = Cr, Mn; Y = Fe, Co and Ni; z = 0.5,1,1.5). It is seen that the magnetic moment is induced by the substitution of ferromagnetic materials with TiX2alloys.

scholarly journals Electronic and structural properties of rare earth pnictides

2016 ◽  
Vol 34 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Ramakant Bhardwaj
Keyword(s):  
Rare Earth ◽  
Electronic Band Structure ◽  
Local Density ◽  
Structural Parameters ◽  
Structural Phase ◽  
Tight Binding ◽  
Lattice Parameter ◽  
Type Structure ◽  
Present Calculation ◽  
Electronic Band

AbstractIn the present paper structural and electronic properties of rare earth pnictides have been presented. The present calculation has been performed using self-consistent tight binding linear muffin tin orbital (TB-LMTO) method within the local density approximation (LDA). The studied compounds undergo a structural phase transition from NaCl-type structure to CsCl-type structure. The electronic band structure and density of states of the pnictides have been reported. The equilibrium lattice parameter a (Å), bulk modulus B (GPa), number of f-states at the Fermi level Nf (states/Ry cell) and volume collapse of AmBi and CmBi have also been reported. The calculated equilibrium structural parameters are in good agreement with the available experimental results.

FIRST-PRINCIPLE STUDY OF STRUCTURAL AND ELECTRONIC PROPERTIES OF CUBIC STRONTIUM TITANATE

2013 ◽  
Vol 22 ◽  
pp. 340-345
Author(s):  
AVINASH DAGA ◽  
SMITA SHARMA ◽  
K. S. SHARMA
Keyword(s):  
Bulk Modulus ◽  
Charge Density ◽  
Electronic Properties ◽  
Local Density ◽  
Computer Code ◽  
Lattice Parameter ◽  
Plane Wave Expansion ◽  
Structural And Electronic Properties ◽  
Calculated Lattice Parameter ◽  
Good Agreement

We have performed ab-initio investigation of SrTiO3 with cubic structure, and have computed its structural and electronic properties. The calculations are performed using a plane wave expansion within the local density approximation and the pseudopotential approximation. Results are given for the lattice constant, bulk modulus and charge density. The lattice parameter and bulk modulus calculated for SrTiO3within LDA are 3.908 Å and 184.6832 GPa respectively. It is found that the calculated lattice parameter and bulk modulus are in good agreement with the available experimental data. The charge density plots show higher accumulation of charge around the boundary and corners. All these calculations have been carried out using ABINIT computer code.

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