First-principles investigation of the structural properties of Mg 1-x Bi x O Gladys Patricia Abdel Rahim 1 , Jairo Arbey Rodríguez Martínez 2 , María Guadalupe Moreno-Armenta 3 1,2 Universidad Nacional de Colombia, Bogotá, Colombia 3 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Ensenada, BC, México . RESUMEN Using the method in first-principles, we have investigated the structural properties of the compound Bi1- xMgxO with varying concentrations of 0%, 25%, 50%, 75% and 100% x of bismuth in the phases in sodium chloride (NaCl), cesium chloride (CsCl), zinc-blende (ZnB), wurtzite (WZ) and nickel arsenidine (NiAs) (including spin). We have found a minimum in all the graphs of energy of cohesion versus the volume of the cell unit, which indicates that the material is stable or to the less metastable in these phases. The exchange and correlation effects are treated by using the Generalized Gradient Approximation (GGA) as it is implemented in the Perdew - Burke- Ernzerhof- method (PBE). Ultrasoft pseudo-potential were employed. The calculations were performed using the pwscf code, distributed with the Quantum-ESPRESSO package. RESULTADOS Conclusions Calculations of structural properties of Mg 1-x Bi x O were carried out by means of DFT using the Wu-Cohen GGA approximation. It was determined that at concentrations of 25% there are no phase transitions, while for 100%, 75%, and of 50% x of Bi, if it exists, this can be very useful for future experimental studies of these materials. Furthermore, it was observed that decreasing the lattice constant makes the material become more rigid and hence increases the bulk modulus and the energy. . E vs. V for the MgO compound in five structures E vs. v for the Mg 0.75 Bi 0.25 O . E vs. v for the Mg 0.50 Bi 0.50 O . E vs. v for the Mg 0.25 Bi 0.75 O Enthalpy vs. pressure for the MgO Enthalpy vs. pressure for the Mg 0.50 Bi 0.50 O Enthalpy vs. pressure for the Mg 0.25 Bi 0.75 O NaCl CsCl ZnS NiAs WZ V [Å 3 ] 79.61 92.09 101.68 104.96 100.78 E[eV] -2491.37 -2487.38 -2491.09 -2487.59 -2491.15 c/a 2.8284 2.8284 2.8284 1.8562 3.23 Structural parameters of the compound MgO NaCl CsCl ZnS NiAs WZ V [Å 3 ] 105.11 109.89 127.95 131.93 128.14 E[eV] -2574.73 -2571.96 -2574.70 -2571.75 -2574.73 c/a 2.8284 2.8284 2.8284 2.008 3.240 Structural parameters of the compound Mg 0.75 Bi 0.25 O NaCl CsCl ZnS NiAs WZ V [Å 3 ] 121.72 120.93 147.65 147.86 148.19 E[eV] -2658.94 -2656.88 -2658.94 -2656.52 -2658.94 c/a 2.8284 2.8284 2.8284 2.1339 3.22 Structural parameters of the compound Mg 0.5 Bi 0.5 O NaCl CsCl ZnS NiAs WZ V [Å 3 ] 135.00 138.59 163.69 164.04 261,78 E[eV] -2743.54 -2741.61 -2743.47 -2741.39 -2743,96 c/a 2.8284 2.8284 2.8284 -2741.39 3,098 Structural parameters of the compound Mg 0.25 Bi 0.75 O

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First-principles investigation of the structural properties of Mg1-xBixO

Gladys Patricia Abdel Rahim1, Jairo Arbey Rodríguez Martínez 2 , María Guadalupe Moreno-Armenta3

1,2Universidad Nacional de Colombia, Bogotá, Colombia3 Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Ensenada, BC, México

RESUMENUsing the method in first-principles, we have investigated the structural properties of the compound Bi1-xMgxO with varying concentrations of 0%, 25%, 50%, 75% and 100% x of bismuth in the phases in sodium chloride (NaCl), cesium chloride (CsCl), zinc-blende (ZnB), wurtzite (WZ) and nickel arsenidine (NiAs) (including spin). We have found a minimum in all the graphs of energy of cohesion versus the volume of the cell unit, which indicates that the material is stable or to the less metastable in these phases. The exchange and correlation effects are treated by using the Generalized Gradient Approximation (GGA) as it is implemented in the Perdew - Burke- Ernzerhof- method (PBE). Ultrasoft pseudo-potential were employed. The calculations were performed using the pwscf code, distributed with the Quantum-ESPRESSO package.

RESULTADOS

ConclusionsCalculations of structural properties of Mg1-xBixO were carried out by means of DFT using the Wu-Cohen GGA approximation. It was determined that at concentrations of 25% there are no phase transitions, while for 100%, 75%, and of 50% x of Bi, if it exists, this can be very useful for future experimental studies of these materials. Furthermore, it was observed that decreasing the lattice constant makes the material become more rigid and hence increases the bulk modulus and the energy. .

E vs. V for the MgO compound in five structures E vs. v for the Mg0.75Bi0.25O . E vs. v for the Mg0.50Bi0.50O . E vs. v for the Mg0.25Bi0.75O

Enthalpy vs. pressure for the MgO Enthalpy vs. pressure for the Mg0.50Bi0.50O Enthalpy vs. pressure for the Mg0.25Bi0.75O

NaCl CsCl ZnS NiAs WZ

V [Å3] 79.61 92.09 101.68 104.96 100.78

E[eV] -2491.37 -2487.38 -2491.09 -2487.59 -2491.15

c/a 2.8284 2.8284 2.8284 1.8562 3.23

Structural parameters of the compound MgO

NaCl CsCl ZnS NiAs WZ

V [Å3] 105.11 109.89 127.95 131.93 128.14

E[eV] -2574.73 -2571.96 -2574.70 -2571.75 -2574.73

c/a 2.8284 2.8284 2.8284 2.008 3.240

Structural parameters of the compound Mg0.75Bi0.25O