Magnetic field effects in the cooperative Jahn-Teller system TbVO4

Effects of a magnetic field on the behaviors of TbVO₄ which shows a cooperative Jahn-Teller phase transition have been investigated. The possibility that the system will return to the undistorted phase at low temperatures in a magnetic field is considered. We show that because of the weak coupling of the system to the magnetic field applied along the c-axis, the magnetic field required to see the transition of the crystal back to the undistorted phase is impractically high. Diluting the crystal with nonmagnetic ions is then a plausible approach in the study of this novel behavior of the system. We have also calculated the effects of a magnetic field applied in the basal plane and shown that the crystal would remain distorted for all temperatures except the cases when the field is applied along the crystallographic axes. Finally, we consider the effects of a magnetic field on the temperature behavior of the specific heat and show that the Schottky anomaly which occurs at a very low temperature (～1°K) will be shifted to a higher temperature by applying a magnetic field.