Magnetic properties of CuSb 2− xTa xO 6 with tri-rutile structure

Abstract

We report magnetic properties of CuSb 2− x Ta x O 6 with tri-rutile type structure. Solubility limit was determined to be x=1.0 by the solid-state reaction and X-ray diffraction measurements. The value of J, the magnetic interaction obtained by Bonner–Fisher fitting, was found to decrease gradually with Ta content x. The value of T N also decreases with x and seems to be zero at x=0.6. As a result of our structural analysis, this fact shows the crossover from one-dimensional to two-dimensional magnetic system with a local distortion caused by Ta substitution. Although the ground state of the compound with x>0.6 is not clear, it can be considered that the long-range antiferromagnetic order disappears and that the quantum critical regime such as a spin-singlet state is realized in this system.