Synthesis, magnetic properties and electronic structure of the S = 1/2 uniform spin chain system InCuPO < inf > 5 < /inf >

Abstract

We have studied the structural and magnetic properties and electronic structure of the compound InCuPO5 synthesized by a solid state reaction method. The structure of InCuPO5 comprises S = 1/2 uniform spin chains formed by corner-shared CuO4 units. Magnetic susceptibility (Χ(T)) data show a broad maximum at about 65 K, a characteristic feature of one-dimensional (1D) magnetism. The Χ(T) data are fitted to the coupled S = 1/2 Heisenberg antiferromagnetic (HAFM) uniform chain model that gives the intra-chain coupling (J/kB) between nearest-neighbor Cu2+ ions as -100 K and the ratio of inter-chain to intra-chain coupling (J'/J) as about 0.07. The exchange couplings estimated from the magnetic data analysis are in good agreement with the values computed from the electronic structure calculations based on the density functional theory + Hubbard U (DFT + U) approach. The combination of theoretical and experimental analysis confirms that InCuPO5 is a candidate material for weakly coupled S = 1/2 uniform chains. A detailed theoretical analysis of the electronic structure further reveals that the system is insulating with a gap of 2.4 eV and a local moment of 0.70 μB/Cu.