| Texto completo | |
| Autor(es): |
de Oliveira, Leonardo S.
;
Sabino, Fernando P.
;
de Florio, Daniel Z.
;
Janotti, Anderson
;
Dalpian, Gustavo M.
;
Souza, Jose A.
Número total de Autores: 6
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Journal of Physical Chemistry C; v. 124, n. 41, p. 10-pg., 2020-10-15. |
| Resumo | |
A comprehensive study on the correlations of structural, magnetic, and electronic properties of a new disordered Nd2CoFeO6 double perovskite has been conducted. The lack of A strong divergence of the magnetic susceptibility suggests competition between magnetic interactions at the magnetic phase transition T-N = 246 K, which is confirmed by the absence of a heat capacity peak. The magnetic susceptibility results indicate that the Fe/Co spins form a classical noninteracting paramagnetic state above T approximate to 2.2T(N), while deviations are found at intermediate temperatures indicating the presence of strong short-range magnetic interactions. AC and DC electrical resistivity results reveal a melting of insulating polaronic behavior to a metallic-like conductivity, establishing an electronic crossover closely related to both local magnetic moment and lattice-parameter evolution. We show from density functional calculations that the magnetic configurations have a strict relation to this crossover, being associated to a transition from low to high spin states of Co3+ ions. This insulator-metal transition has its origin driven by a local increase in the magnetic moment of Co3+ ions. Our results point to a scenario in which a continuous spin-state transition triggers a crossover between distinct electronic states from the insulating polaronic behavior to permanent metallic states. (AU) | |
| Processo FAPESP: | 17/02317-2 - Interfaces em materiais: propriedades eletrônicas, magnéticas, estruturais e de transporte |
| Beneficiário: | Adalberto Fazzio |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |
| Processo FAPESP: | 18/15682-3 - Síntese e caracterização das propriedades físicas de materiais semicondutores micro/nano estruturados |
| Beneficiário: | José Antonio Souza |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |
| Processo FAPESP: | 15/24999-2 - Novos compostos cerâmicos para células a combustível de óxidos sólidos protônicas |
| Beneficiário: | Daniel Zanetti de Florio |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |
| Processo FAPESP: | 19/21656-8 - Métodos de Big Data para ajustar perovskitas às propriedades alvo: ligas, defeitos e dopagem |
| Beneficiário: | Fernando Pereira Sabino |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |