Magnetism of the antiferromagnetic spin-$\frac{3}{2}$ dimer compound CrVMoO${}_7$ having an antiferromagnetically ordered state

Abstract

We measured magnetization, specific heat, electron spin resonance, neutron diffraction, and inelastic neutron scattering of CrVMoO${}_7$ powder. An antiferromagnetically ordered state appears below $T_{\mathrm{N}}=26.5\pm 0.8$ K. We consider that the probable spin model for CrVMoO${}_7$ is an interacting antiferromagnetic spin-$\frac{3}{2}$ dimer model. We evaluated the intradimer interaction $J$ to be $25\pm 1$ K and the effective interdimer interaction $J_{\mathrm{eff}}$ to be $8.8\pm 1$ K. CrVMoO${}_7$ is a rare spin dimer compound that shows an antiferromagnetically ordered state at atmospheric pressure and zero magnetic field. The magnitude of ordered moments is $0.73(2){\mu }_{\mathrm{B}}$. It is much smaller than a classical value $\sim 3{\mu }_{\mathrm{B}}$. Longitudinal-mode magnetic excitations may be observable in single crystalline CrVMoO${}_7$.

8 pages, 9 figures, 1 table