PROPRIEDADES TÉRMICAS E MAGNÉTICAS DOS BOROCARBETOS / THERMAL AND MAGNETIC PROPERTIES OF A SERIES OF BOROCARBIDES

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

We propose a spin hamiltonian to describe the magnetic and thermal properties of a series of borocarbides. The effect of the crystal electric field is simulated by an effective magnetic field. By applying spin wave theory we have found the dispersion relation and the density of state for the magnos as well. In presence of an external magnetic field this density os state shifts rigidly in energy. From these results we have calculated the magnon contribuition to the molar specific heat without applied magnetic field. the effect of the field, however, is very small. We also have found the sublattice magnetization at T = 0K which is slightly reduced with respect to the ionic value given by the Hund s rule. Then we have calculated the sublattice magnetization as a function of T, both in presence and in absence of the magnetic field. With this model we succed in fitting fairly well the experimental data for the specific heat of the borocarbides series.

ASSUNTO(S)

borocarbides magnetization spin wave calor especifico borocarbonetos ondas de spin specific heat magnetizacao

ACESSO AO ARTIGO

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