Contribuição magnetoelastica para as constantes elasticas do terbio monocristalino

AUTOR(ES)

Milton Starosta Torikachvili

DATA DE PUBLICAÇÃO

1978

RESUMO

We have investigated the behavior of the 2nd order elastic constants of single-crystal terbium, with the state of magnetization of the material, in magnetic fields up to 73 kOe, between 4.2 and 300 K, range that includes 3 kinds of magnetic ordering: ferromagnetic , helical antiferromagnetic ( T<221 K ) and paramagnetic (221 K 229 K ). The elastic constants were determined with ultrasonic techniques and the magnetization curves were obtained with a vibrating sample magnetometer, in the same sample. We develop a model to calculate the dependence of the elastic constants on magnetization, in which the magnetoelastic interactions are treate up to 2nd order in the strains and the 3rd order elastic energy is not neglected. We apply this model to the paramagnetic region and the observed experimental results indicate that this treatment is adequate. To analise qualitative and quantitatively the results of this model. we develop a numerical model in which, to avoid treating a very large number of magnetoelastic coupling constants, we make many aproximations. With this, we search for just a qualitative description of the observed results, in which we are successful

ASSUNTO(S)

fisica do estado solido

Documentos Relacionados

• Contribuição magnetoelastica as constantes elasticas do holmio
• Estudo da contribuição magnetoelastica para as constantes elasticas do holmio
• Transições de fase magneticas e constantes elasticas do erbio monocristalino
• Propriedades eletrônicas, estruturais e constantes elásticas do ZnO
• Constantes elasticas, atenuação ultrasonica e efeito termico anomalo nas terras raras : Gd, Tb, Er