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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Scaling behavior of nearly first order magnetic phase transitions

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Autor(es):
Ferreira, P. M. G. L. [1] ; Souza, J. A. [1]
Número total de Autores: 2
Afiliação do(s) autor(es):
[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09090400 Santo Andre, SP - Brazil
Número total de Afiliações: 1
Tipo de documento: Artigo Científico
Fonte: JOURNAL OF PHYSICS-CONDENSED MATTER; v. 23, n. 22 JUN 8 2011.
Citações Web of Science: 3
Resumo

A scaling behavior between heat capacity C(P){*} and thermal expansion coefficient times temperature Omega T lambda, where. is a scale factor, is obtained for ferromagnetic La(1-x)Ca(x)MnO(3) with x = 0.20, 0.25, 0.30, 0.34, 0.40, and 0.45 compounds. The pressure derivative of the magnetic phase transition temperature obtained through a scaling method is in good agreement with experimental results for all samples. The critical exponents associated with the specific heat (alpha) for x = 0.25, 0.30, and 0.34 are very close to the phase boundary where continuous phase transitions become discontinuous. This is attributed to strong coupling among the spin, charge, and lattice degrees of freedom, which indicates that the magnetization alone would be a poor choice for the order parameter in these systems. Based on thermodynamic arguments, a phase diagram with diverging, cusp-like, near first order, and first order phase transitions is presented. (AU)

Processo FAPESP: 09/18618-5 - Síntese de materiais e caracterização das suas propriedades termodinâmicas e transporte elétrico
Beneficiário:José Antonio Souza
Linha de fomento: Auxílio à Pesquisa - Regular