Materials Science Forum, Vol.514-516, 319-322, 2006
Analysis of phase transitions in La and Nd substituted YIG with magnetic disaccommodation measurement
The magnetic disaccommodation on polycrystalline Nd doped YIG Nd(x)y(3-x)Fe(5)O(12) (0 < x < 2.5) and La doped YIG LaxY3-xFe5O12 (0 < x < 0.7) is studied in this work. A different behaviour with the sintering atmosphere and the dopant has been observed. For Nd doped garnets sintered in air the characteristic peak of disaccommodation in YIG shifts from 120 K to 100 K; for x=2.0 an additional 300 K peak is observed, due to the presence of magnetite in the sample, thus indicating that phase transition has been reached. In CO2 sintered samples, the process at 120 K exhibit magnetic accommodation features and the phase transition takes place at a lower doping rate. On the contrary, CO2 sintered La doped samples do not show magnetic accommodation as Nd doped YIG, but normal disaccommodation processes, with the solubility limit observed at x=0.3, whereas in air sintered samples the phase transition is not observed with disaccommodation measurements.