Structural and magnetic properties in the quantum S=1/2 dimer system Ba-3(Cr1-xVx)(2)O-8 with site disorder

Article

关键词: BOSE-EINSTEIN CONDENSATION;    SINGLET-GROUND-STATE;    CHOPPER SPECTROMETER;    SPIN GAP;    TRANSITION;   

DOI  :  10.1103/PhysRevB.87.144427

来源: SCIE

【 摘 要 】

We report a comprehensive study of dc susceptibility, specific-heat, neutron-diffraction, and inelastic neutron-scattering measurements on polycrystalline Ba-3(Cr1-xVx)(2)O-8 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. DOI: 10.1103/PhysRevB.87.144427

【 授权许可】

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