A MOSSBAUER STUDY OF TEMPERATURE-DRIVEN SPIN-REORIENTATION TRANSITIONS IN TBFEO3

Reorientations of Fe3+ spins have been studied in TbFeO3 single-crysta l absorbers by Mossbauer spectroscopy. At low temperature we observed two closely spaced changes of direction of the Fe3+ Spins. Below 6.5 K the spins moved from the a towards the c orthorhombic axis with decre asing temperature. This movement was reversed at approximately 4.2 K a nd the movement back to the a axis was complete at 3.5 K. The maximum deviation from the a axis was about 55-degrees and somewhat dependent on crystal stress. These rotations are attributed to the temperature d ependence of the Fe-Tb and Tb-Tb interactions.