Novel low-dimensional spin 1/2 antiferromagnets: Two-halide exchange pathways in A2CuBr4 salts

Abstract

Magnetic susceptibility studies of several A2CuBr4 salts, where A is an organoammonium cation, are reported. These salts contain tetrahedrally distorted CuBr2−4 anions. Magnetic exchange pathways exist through interanionic Br⋅⋅⋅Br pathways. In this manner, various types of new antiferromagnetic spin 1/2 magnetic systems have been obtained. As examples, a one-dimensional chain, a coupled pair of chains or ‘‘ladder,’’ a two-dimensional square lattice, and a distorted ‘‘honeycomb’’ lattice are discussed.