EFFECTS OF HOLE-DOPING AND DISORDER ON THE MAGNETIC STATES OF DELAFOSSITE CuCrO2 HAVING A SPIN-3/2 ANTIFERROMAGNETIC TRIANGULAR SUBLATTICE

Abstract

In this review, we will discuss the effects of itinerant hole and disorder produced by substitutions on the magnetic states of polycrystalline delafossite oxide CuCrO 2 having a spin-3/2 antiferromagnetic triangular sublattice. First, we will show the effects of hole-doping by the substitution of nonmagnetic Mg 2+ for magnetic Cr 3+ on the physical properties of CuCrO 2, and will discuss the origin of nontrivial promotion of the 120° Néel state due to the coupling between the itinerant hole and localized spin. Next, we will show the effects of disorder introduced by the isovalent substitutions such as the nonmagnetic Ag + substitution for nonmagnetic Cu + and the nonmagnetic Al 3+ one for magnetic Cr 3+, and will discuss the possibility of appearance of unusual magnetic states such as spin liquid or spin nematic states.