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

In this review, we will discuss the effects of itinerant hole and disorder produced by substitutions on the magnetic states of polycrystalline delafossite oxide CuCrO2 having a spin-3/2 antiferromagnetic triangular sublattice. First, we will show the effects of hole-doping by the substitution of nonmagnetic Mg2+ for magnetic Cr3+ on the physical properties of CuCrO2, and will discuss the origin of nontrivial promotion of the 120° Neel 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 Al3+ one for magnetic Cr3+, and will discuss the possibility of appearance of unusual magnetic states such as spin liquid or spin nematic states.