Aplicação do Modelo de Preisach em Ímãs Nanocristalinos

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Author(s):	Daniel Reinaldo Cornejo Total Authors: 1
Document type:	Doctoral Thesis
Press:	São Paulo.
Institution:	Universidade de São Paulo (USP). Instituto de Física (IF/SBI)
Defense date:	1998-05-28
Examining board members:	Frank Patrick Missell; Carlos Castilla Becerra; Jose Roberto Cardoso; Alberto Passos Guimarães Filho; Fernando Jose Gomes Landgraf
Advisor:	Frank Patrick Missell
Abstract
We studied the magnetic properties of nanocrystalline Sm-Fe-Co alloys. These alloys were prepared by mechanical alloying and subsequent annealing. We obtained nanocrystalline rnagnets of composition Sm18 (Fe, Co )82 , for which the main hard magnetic phase is Sm(Fe, Co)82. The alloys showed excellent magnetic properties: relative remanence Mn/ Ms :2; 0.6 and coercive fields ranging from 5 to 20 k0e, depending upon the amount of Fe present. Henkel plots were used in order to study magnetic interactions in these alloys. The influence of the interactions and the demagnetized state on the Henkel plots was also studied. (AU)