Magnetic and magnetoelastic properties of valence transition compounds based on YbInCu4 (Review Article)

The intermetallic compound YbInCu4 undergoes an isostructural first-order valence-changing phase transition from a state with localized moments of the Yb into a Fermi liquid state with strong Kondo screening. This article reviews studies of the structure and of the electronic, magnetic, and magnetoelastic properties of compounds based on YbInCu4. The effects of alloying and pressure on such parameters of the electronic and magnetic state as the Kondo temperature, Curie paramagnetic temperature, effective magnetic moment, and valence of Yb are determined. The observational data are interpreted in terms of a single-impurity Kondo model. The magnetic anisotropy of single-crystal YbInCu4 and magnetostriction in high magnetic fields are studied. It is shown that a crystal field model for localized states of Yb3+ provides a good description of magnetic anisotropy and anisotropic magnetostriction in the high-temperature phase.