Stability of metallic, magnetic and electronic states in NaZn_(13)-type La(Fe_xSi_(1-x))_(13) magnetocaloric compounds

摘要

To establish better magnetocaloric performances in NaZn_(13)-type La(Fe_xSi_(1-x))_(13), its fundamental properties were examined. A growth rate of La(Fe_xSi_(1-x))_(13) phase against homogemzation is governed by reaction diffusion. The volume dependence of the Curie temperature after hydrogenation elucidates the role of the magnetovolume effect. Similar results are obtained for the partial substitution by Pr, while those by Ce are influenced by band hybridization. Occupation of Si at the 96i site stabilizes the ferromagnetic phase and the double-minimum structure of the free energy.