The magnetic susceptibility and electronic specific heat of transition metals in relation to their electronic structure

Abstract

Information may be obtained about the electronic structure of transition metals by a proper theoretical analysis of the results of experiments of various types, two of which are considered in detail. The collective electron treatment of electronic specific heat and magnetic susceptibility is described, and expressions are obtained for the main relations in a form suitable for application to the experimental results. The density of states at the top of the electron energy band may be derived from the electronic contribution to the specific heat at low temperatures, and from this, combined with results for the magnetic susceptibility, a quantitative measure of the quasi-magnetic interaction may be obtained. The experimental results for the transition metals are collected together and critically discussed. It is shown that the paramagnetic susceptibility is higher than that estimated from the electronic specific heat assuming no additional interactions, and that the positive quasiferromagnetic interaction indicated is of the same order of magnitude as in the ferromagnetic metals. Recent experimental work on both the specific heat and susceptibility at low temperatures of alloys of palladium is discussed with particular reference to the determination of the forms of electronic energy bands. Theoretical work on the properties associated with bands of various forms is also described, and an interpretation is given of some of the more unusual types of temperature variation of susceptibility such as that observed for palladium. The coordination of the electronic properties of the transition metals provided by the electron energy band scheme though partial is very promising, but much further experimental work on metals and alloys at low temperatures will be required before a satisfactory overall picture can be obtained.