Cpa Approximation
Mostrando 1-4 de 4 artigos, teses e dissertações.
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1. ESTUDO DO PARÂMETRO DE ORDEM E DO MOMENTO MAGNÉTICO EM BOROCARBETOS PSEUDOQUATERNÁRIOS / STUDY OF ORDER PARAMETER AND MAGNETIC MOMENT IN PSEUDOQUATERNARY BOROCARBIDES
Experimental data show that the dissolved impurities of the Mn presents a magnetic moment when substitute the Ni atom in pseudoquaternary borocarbide Y (Ni(1−x)Mx)2B2C, this is not observed if the impurities are Fe and Co. In this work we do a theoretical study of the superconducting order parameter variation and a possible formation of impurities magn
Publicado em: 2007
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2. Theoretical calculus of magnetocaloric effects of La(FexSi1-x)13. / Cálculo teórico do efeito magnetocalórico do composto La(FexSi1-x)13.
The study of the magnetocaloric effect of the compound La(FexSi1-x)13 became very important, once recent experiments revealed that this compound exhibits great values of the isothermal entropy change (Δ S) and the adiabatic temperature change(ΔTad), which are the quantities used to characterize the power of refrigeration of any compound. We studied
Publicado em: 2006
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3. Modelo de Anderson para duas impurezas : Metodo dos campos efetivos / The two-impurity Anderson model : an effective medium approach
O Hamiltoniano do modelo de Anderson para duas impurezas é estudado via um desacoplamento das funções de Green. Neste caso resulta ser equivalente a aproximação de potencial coerente (CPA) que também, neste caso, coincide com a aproximação Hubbard-I. Consideram-se todos os termos de interação impureza-impureza, tanto os denominados termos de um cor
Publicado em: 2004
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4. Propriedades eletrônicas do monocalcogenetos de Sm e de ligas do tipo Sm1-xMxS
We present a theoretical model to explain the valence transitions of Sm in Sm1-xMxS alloys, where M is a transition metal (e.g. Y or La) as a function of the concentration x. The system is described by a two-band model: a zero width band of energy E0 (the 4f-level of Sm) and a conduction band, which is treated in the coherent potencial approximation (CPA). T
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 1981