Effects of Native Vacancies on Nb-Doped MgH 2 Using Density Functional Theory Calculations

In the present work, we considered the effect of Nb and charged vacancies on the properties of magnesium hydride. We performed spin-polarized ab initio calculations substituting an Mg atom by an Nb impurity. Then, some charged vacancies were included in the MgH 2 + Nb system (V H , V Mg , or V Mg-H...

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Detalhes bibliográficos
Autores: Gaztañaga, Francisco, Luna, Carla Romina, Orazi, Valeria, Gonzalez, Estela Andrea, Faccio, Ricardo, Jasen, Paula Verónica
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2018
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/93614
Acesso em linha:http://hdl.handle.net/11336/93614
Access Level:acceso abierto
Palavra-chave:VACANCIES
Nb
DFT
MgH2
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Descrição
Resumo:In the present work, we considered the effect of Nb and charged vacancies on the properties of magnesium hydride. We performed spin-polarized ab initio calculations substituting an Mg atom by an Nb impurity. Then, some charged vacancies were included in the MgH 2 + Nb system (V H , V Mg , or V Mg-H ). In each case, three possible charge states were considered (+1, 0, or -1). We computed cohesion and formation energies, band gap, and magnetic moment. We also calculated the transition level energy value and the density of states. Nb states are located in the gap, and a magnetic moment is induced. In the case of the system with charged vacancies, we found that V H + and V H 0 are the more probable vacancies formed, and the states near the Fermi level (E F ) are filled, thus getting an important reduction in the band gap.