Development of simple model for size and shape dependence of critical temperature for ferromagnetic nanomaterials

摘要

Based on bond energy model, the size and shape dependent critical temperature T_c(D) of ferromagnetic nanomaterials is modeled in a simplified form without any adjustable parameter. Here, D denotes the size of nanoparticle. We considered different shapes viz. film, dodecahedral, icosahedral, wire, spherical, octahedral and tetrahedral. The results obtained are compared with the available experimental data as well as the earlier formulation available in the literature. It is found that the model proposed in the present paper gives a better agreement with the experimental data as compared with earlier formulation. Due to the simplicity and applicability of the model, it may be extended to different types of nanomaterials.