| Texto completo | |
| Autor(es): |
Tartaglia, R.
;
Arantes, F. R.
;
Galdino, C. W.
;
Rigitano, D.
;
Kaneko, U. F.
;
Avila, M. A.
;
Granado, E.
Número total de Autores: 7
|
| Tipo de documento: | Artigo Científico |
| Fonte: | PHYSICAL REVIEW B; v. 99, n. 9, p. 6-pg., 2019-03-20. |
| Resumo | |
The series of intermetallic compounds RNiSi3 (R = rare earth) shows interesting magnetic properties evolving with R and metamagnetic transitions under applied magnetic field for some of the compounds. The microscopic magnetic structures must be determined to rationalize such rich behavior. Here, resonant x-ray magnetic diffraction experiments are performed on single crystals of GdNiSi3 and TbNiSi3 at zero field. The primitive magnetic unit cell matches the chemical cell below the Neel temperatures T-N = 22.2 and 33.2 K, respectively. The magnetic structure is determined to be the same for both compounds (magnetic space group Cmmm'). It features ferromagnetic ac planes that are stacked in an antiferromagnetic + - + - pattern, with the rare-earth magnetic moments pointing along the (a) over arrow direction, which contrasts with the + - - + stacking and moment direction along the (b) over arrow axis previously reported for YbNiSi3. This indicates a sign reversal of the coupling constant between second-neighbor R planes as R is varied from Gd and Tb to Yb. The long b lattice parameter of GdNiSi3 and TbNiSi3 shows a magnetoelastic expansion upon cooling below T-N, pointing to the conclusion that the + - + - stacking is stabilized under lattice expansion. A competition between distinct magnetic stacking patterns with similar exchange energies tuned by the size of R sets the stage for the magnetic ground state instability observed along this series. (AU) | |
| Processo FAPESP: | 14/20365-6 - Preparação e caracterização de novos clatratos termoelétricos contendo terras raras trivalentes e aceitadores mistos |
| Beneficiário: | Fabiana Rodrigues Arantes |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |
| Processo FAPESP: | 17/04913-1 - Estruturas e Transições Magnéticas em RNiSi3 (R:Gd-Ho) |
| Beneficiário: | Rodolfo Tartaglia Souza |
| Modalidade de apoio: | Bolsas no Brasil - Mestrado |
| Processo FAPESP: | 11/19924-2 - Estudo e desenvolvimento de novos materiais avançados: eletrônicos, magnéticos e nanoestruturados: uma abordagem interdisciplinar |
| Beneficiário: | Carlos Rettori |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |