Curie temperature of RE<inf>2</inf>Fe<inf>17</inf> compounds - A Friedel model approach

The variations of Curie temperature (TC) of RE2Fe17 compounds upon substitutional and interstitial modifications are qualitatively explained using a simple phenomenological equation TC = Cμ2efff(λ/d). Here μeff is the effective magnetic moment/atom and f(λ/d) is a monotonically increasing function of (λ/d), where λ is the Friedel length scale and d is the distance between nearest magnetic atoms. The TC variation of substituted compounds can be understood by incorporating the effects of magnetic dilution and charge transfer whereas, in interstitially modified compounds the TC variation can be explained primarily by incorporating the effects of band narrowing. Also, the effect of pressure on the TC is understood by incorporating band broadening effects in the Friedel model. © 1998 Elsevier Science Ltd. All rights reserved.