Artículos de revistas
Heat Flux Measurements Of Tb3m Series (m=co, Rh And Ru): Specific Heat And Magnetocaloric Properties
Registro en:
Physica B: Condensed Matter. Elsevier, v. 503, p. 64 - 69, 2016.
0921-4526
10.1016/j.physb.2016.09.007
2-s2.0-84988470741
Autor
Monteiro J.C.B.
Lombardi G.A.
dos Reis R.D.
Freitas H.E.
Cardoso L.P.
Mansanares A.M.
Gandra F.G.
Institución
Resumen
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) We report on the magnetic properties and magnetocaloric effect (MCE) for the Tb3M series, with M=Co, Rh and Ru, obtained using a heat flux technique. The specific heat of Tb3Co and Tb3Rh are very similar, with a first order type transition occurring around 6 K below the magnetic ordering temperature without any corresponding feature on the magnetization. The slightly enhanced electronic specific heat, the Debye temperature around 150 K and the presence of the magnetic specific heat well above the ordering temperature are also characteristic of many other compounds of the R3M family (R=Rare Earth). The specific heat for Tb3Ru, however, presents two peaks at 37 K and 74 K. The magnetization shows that below the first peak the system presents an antiferromagnetic behavior and is paramagnetic above 74 K. We obtained a magnetocaloric effect for M=Co and Rh, −∆S=12 J/kg K, but for Tb3Ru it is less than 3 J/kg K (μ0∆H=5 T). We believe that the experimental results show that the MCE is directly related with the process of hybridization of the (R)5d-(M)d electrons that occurs in the R3M materials. © 2016 Elsevier B.V. 503 64 69 CAPES, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior CNPq, Conselho Nacional de Desenvolvimento Científico e Tecnológico FAPESP, Fundação de Amparo à Pesquisa do Estado de São Paulo Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)