Electronic and crystallographic structure, hard x-ray photoemission, and mechanical and transport properties of the half-metallic Heusler compound Co2MnGe

• Autor(a) principal: Ouardi, Siham
• Data de Publicação: 2011
• Outros Autores: Fecher, Gerhard H., Balke, Benjamin, Beleanu, Andreea, Kozina, Xeniya, Stryganyuk, Gregory, Felser, Claudia, Klöß, Werner, Schrader, Hartmut, Bernardi, Fabiano, Morais, Jonder, Ikenaga, Eiji, Yamashita, Yoshiyuki, Ueda, Shigenori, Kobayashi, Keisuke
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/104527
• topic: Física da matéria condensada; Materiais ferromagnéticos; Momentos magnéticos; Estrutura cristalina; Estrutura eletrônica; Estrutura fina estendida de absorção de raios x (EXAFS); Ligas de cobalto; Ligas de manganês; Calculos ab initio; Estequiometria; Vibracoes

This work reports on the electronic and crystalline structure and the mechanical, magnetic, and transport properties of the polycrystalline Heusler compound Co2MnGe. The crystalline structure was examined in detail by extended x-ray absorption fine-structure spectroscopy and anomalous x-ray diffraction. The compound exhibits a well-ordered L21 structure as is typical for Heusler compounds with 2:1:1 stoichiometry. The low-temperature magnetic moment agrees well with the Slater-Pauling rule and indicates a half-metallic ferromagnetic state of the compound, as is predicted by ab initio calculations. Transport measurements and hard x-ray photoelectron spectroscopy were performed to explain the electronic structure of the compound. The obtained valence band spectra exhibit small energy shifts that are the result of the photoexcitation process, whereas electron-electron correlation in the ground state is negligible. The vibration and mechanical properties of the compound were calculated. The observed hardness values are consistent to a covalent-like bonding of Co2MnGe.