1304.6069 (Tao Hong et al.)

Structural and magnetic properties in the quantum S=1/2 dimer systems
Ba3(Cr1-xVx)2O8 with site disorder    [PDF]

Tao Hong, L. Y. Zhu, X. Ke, V. O. Garlea, Y. Qiu, Y. Nambu, H. Yoshizawa, M. Zhu, G. E. Granroth, A. T. Savici, Zheng Gai, H. D. Zhou

We report a comprehensive study of the DC susceptibility, specific heat, neutron diffraction, and inelastic neutron scattering measurements on the polycrystalline Ba3(Cr1-xVx)2O8 samples, where x=0, 0.06, 0.15, and 0.53. A Jahn-Teller structure transition occurs for x=0, 0.06, and 0.15 samples and the transition temperature is reduced upon vanadium substitution from 70(2) K at x=0 to 60(2) K at x=0.06 and 0.15. The structure becomes less distorted as x increases and such transition disappears at x=0.53. The observed magnetic excitation spectrum indicates that the singlet ground state remains unaltered and spin gap energy \Delta=1.3(1) meV is identical within the instrument resolution for all x. In addition, the dispersion bandwidth W decreases with increase of x. At x=0.53, W is reduced to 1.4(1) meV from 2.0(1) meV at x=0.

View original: http://arxiv.org/abs/1304.6069