Theoretical Investigation of Both Size and Shape Effects on Ferromagnetic Nanocrystals Curie Temperature

In this paper we study about both size and shape effects on the Transition temperature of ferromagnetic nanocrystals for the first time. Also a thermodynamic approach is proposed to the mechanism of size and shape dependent of ferromagnetic transition temperature. One relation that is obtained, is a simple and unified function without any adjustable parameter that pre-established for the size dependent of ferromagnetic. Also to find of shape effects on the Curie temperature of ferromagnetic nanoparticles a model was developed, that is based on the relation cohesive energy and temperature variations.