Effects of Fe－Fe bond length change in NaZn₁₃-type intermetallic compounds on magnetic properties and magnetic entropy change

In this paper the effects of Fe－Fe bond length change on magnetic properties and magnetic entropy change have been investigated on LaFe_12.4-xSi_xCo_0.6 and LaFe_12.3-xAl_xCo_0.7 intermetallic compounds. According to the analyses of Fe－Fe bond length change, the variation of Curie temperature and the unusual magnetic phase transition which results in the large magnetic entropy change were explained. The effects of the substitution of Co and Si for Fe on magnetic entropy change and field-induced itinerant-electron metamagnetic transition in LaFe_12.4-xSi_xCo_0.6 compounds were also studied and the considerable magnetic entropy change has been achieved.