| Texto completo | |
| Autor(es): |
Attah-Baah, John M.
;
Silva, Romualdo S.
;
Santos, Cledson
;
Carvalho, Maria H.
;
Ferreira, Nilson S.
Número total de Autores: 5
|
| Tipo de documento: | Artigo Científico |
| Fonte: | ACS OMEGA; v. 10, n. 18, p. 13-pg., 2025-04-30. |
| Resumo | |
A key challenge remains to improve or discover magnetic solids with optimal magnetocaloric effect (MCE) performance, providing a promising and environmentally friendly cooling technology. Herein, we report the crystal structure, magnetocaloric effect, and critical behavior of double perovskite NdSmNiMnO6 synthesized by the modified sol-gel process. X-ray diffraction structural investigation reveals that NdSmNiMnO6 crystallizes in the monoclinic P2 1/n (14) space group. The magnetocaloric analysis unveils a maximum magnetic entropy change of -Delta S M max = 2.38 J kg-1 K-1 (at 0-7 T) near the ferromagnetic to paramagnetic second-order phase transition at 180 K. Furthermore, the estimated relative cooling power value increases from similar to 25 to similar to 182 kg-1 K-1 when the applied field changes up to 0-7 T, suggesting a promisor magnetic refrigerant material. The critical behavior investigated by techniques such as the modified Arrott plot, the Kouvel-Fisher method, and the critical isotherm analysis reliably yields critical exponents beta = 0.469, gamma = 0.978, and delta = 3.09, in agreement with the scaling hypothesis. Lastly, the renormalization group theory analysis revealed a magnetic interaction distance decaying as J(r) proportional to r -4.63, which is between the three-dimensional (3D) Heisenberg and the mean-field models, suggesting that the critical behavior of NdSmNiMnO6 can be attributed to the competition between long- and short-range magnetic interactions. (AU) | |
| Processo FAPESP: | 17/10581-1 - Fenômenos emergentes em sistemas de dimensões reduzidas |
| Beneficiário: | Pascoal Jose Giglio Pagliuso |
| Modalidade de apoio: | Auxílio à Pesquisa - Projetos Especiais |
| Processo FAPESP: | 20/10580-8 - Síntese e caracterização de nanofios de férmions pesados supercondutores da família CeMnIn3n+2 (M = Co, Rh, In; n = 0,1) |
| Beneficiário: | Maria Helena Carvalho da Costa |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |