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ParamagneticIronDoes bcc Fe become a normal metal above Tc? In that case one would expect a T-independent Pauli susceptibility. The following figure  (Fig. 1 from M. Shimitsu, M Sakoh J. Phys. Soc. Jpn. 36 1000 (1974)) shows that a Curie Weiss plot applies instead, hence Fe is not a Pauli paramagnet. The Curie-Weiss law implies an instantaneous moment and an instantaneous exchange with its neighbours, yielding the finite Curie-Weiss temperature Tc. This supports the idea that a local moment on iron must exist, based on nearly localised Fe 3d-band contributions. They are maybe modified by the disappearance of coherent more delocalised electron (s-bands) contributions. This moment is then subject to large thermal fluctuations that justify a Curie-Weiss susceptibility. |