We report the magnetic properties and magnetic structure of the zircon-type compound ${\mathrm{GdVO}}_4$, together with the magnetic structure of the isostructural ${\mathrm{NdVO}}_4$. At $T\simeq 2.5$ K, ${\mathrm{GdVO}}_4$ undergoes a phase transition to antiferromagnetic $G_z$, driven mainly by the exchange interactions, while the magnetic anisotropy and dipolar interactions are minor contributions. Near the liquid-helium boiling temperature, the magnetocaloric effect of ${\mathrm{GdVO}}_4$ is nearly as large as that of the structurally closely related ${\mathrm{GdPO}}_4$. It is noteworthy that ${\mathrm{GdVO}}_4$ has been recently proposed as a good passive regenerator in Gifford-McMahon cryocoolers, since adding a magnetization-demagnetization stage to the cryocooler refrigeration cycle would increase its efficiency for liquefying helium. ${\mathrm{NdVO}}_4$ is a canted $G_z$-type antiferromagnet and shows enhancement of the magnetic reflections in neutron diffraction below ca. 500 mK, due to the polarization of the Nd nuclei by the hyperfine field.

• Received 16 March 2018
• Revised 16 May 2018

DOI:https://doi.org/10.1103/PhysRevB.97.214401