Magnetization study on single-crystalline TbMn6Ge6

The compound TbMn6Ge6 exhibits unusual magnetic properties. Low-field magnetization measurements show that TbMn6Ge6 orders around 450 K. In the whole ordered range, metamagnetic behavior with appreciable hysteresis is observed, both for the field applied parallel and perpendicular to the crystallographic c-direction. The saturation moment of 5 μB/f.u. obtained at temperatures around 300-350 K after the metamagnetic transition that occurs below 1 T suggests collinear ferrimagnetic order of the magnetic Tb and Mn sublattices after the transition. The critical field of the metamagnetic transition increases with decreasing temperature. Also, measurements of the magnetization have been carried out in high magnetic fields up to around 50 T at various temperatures in the ordered region. The magnetic isotherms measured with the field applied along the main crystallographic directions exhibit a wealth of field-induced phase transitions that provide information on the competing interactions in this compound.