Antiferromagnetic-to-ferromagnetic transformation in powdered TDAE-
J. Stefan Institute - Jamova 39, 1001 Ljubljana, Slovenia
Accepted: 27 June 1996
Electron spin resonance measurements on powdered - demonstrate that freshly prepared samples show at first a transition to a low-temperature “antiferromagnetic”-like phase and that on annealing at room temperature they transform to the modification which exhibits a transition to the ferromagnetic ground state. The characteristic time for this transformation is in powdered samples only of several hours, while in single crystals it is of the order of several weeks. The above difference could be due to the different strain distribution which affects the freedom of rotation of the ions and thus the exchange coupling.
PACS: 76.60.Nt – Magnetic annealing and temperature-hysteresis effects / 76.30.-v – Electron paramagnetic resonance and relaxation
© EDP Sciences, 1996