Chapter 2 Dilute transition metal alloys; Spin glasses

Abstract

This chapter discusses dilute transition metal alloys. The subject of dilute transition metal alloys may be divided into two classes of interest: (1) non-interacting or very dilute 3d-magnetic impurities dissolved in a non-magnetic host, which can be classified under the general heading of the Kondo effect—a localized antiferromagnetic interaction of the isolated impurity spins with the surrounding conduction electrons and (2) the impurity spin-spin interactions, which lead to giant moment ferromagnetism and spin glass freezing. These latter two cases represent different examples of magnetic ordering such as a long-range, but nonuniform, ferromagnetic alignment, and a random arrangement of frozen spin-orientations. Both of these effects depend strongly on the conduction electrons to propagate the magnetic interactions over large distances. The boundary between these two dissimilar states of magnetism is controlled by the magnetic behavior of these itinerant electrons. The chapter reviews the listing of alloy systems, experimental properties, and theory of random alloys.