Influence of fluctations on spin systems with spatially isotropic competing interactions

We consider spin systems with competing interactions isotropic with respect to the axes of a cubic lattice. A renormalization-group analysis carried to second order in E=d -4 demonstrates that the criticai behavior for the para-modulated phase transition is 2m-component-like with m = 3 for a uniaxia...

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Detalles Bibliográficos
Autor: Barbosa, Marcia Cristina Bernardes
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:1990
País:Brasil
Institución:Universidade Federal do Rio Grande do Sul (UFRGS)
Repositorio:Repositório Institucional da UFRGS
Idioma:inglés
OAI Identifier:oai:www.lume.ufrgs.br:10183/103597
Acceso en línea:http://hdl.handle.net/10183/103597
Access Level:acceso abierto
Palabra clave:Sistemas de spin
Propriedades magneticas das substancias
Transformações de fase
Descripción
Sumario:We consider spin systems with competing interactions isotropic with respect to the axes of a cubic lattice. A renormalization-group analysis carried to second order in E=d -4 demonstrates that the criticai behavior for the para-modulated phase transition is 2m-component-like with m = 3 for a uniaxially modulated phase and m =4 for a cubically modulated phase, in the same universality class as the m-component spin model with uniaxial competing interactions. Each case may describe ditferent helical magnetic rare-earth alloys. Possible phase diagrams are proposed encompassing such compounds.