Field induced phases in a GMR system TbNiSn

Results of neutron diffraction measurements on TbNiSn in magnetic fields up to 6T are reported. This material shows successive phase transitions at T1 = 7.6 K, T2 = 6.0 K, T3 = 2.0 K and TN = 18.5 K in zero field, and a giant magnetoresistance effect (GMR) near four successive metamagnetic transitions at low temperatures. Propagation vectors and main signatures of the magnetic phases appearing at elevated fields applied along the b axis at low temperatures are determined. We find large hysteresis at several phase boundaries. In some cases a co-existence of magnetic structures is detected.