High‐Temperature Phase Transition of Y4Al2O9

摘要: Reversible thermal phase transition was observed for Y[sub 4]Al[sub 2]O[sub 9] at 1,377 C with a hysteresis width of 78 using differential scanning calorimetry. The enthalpy the ([Delta]H) about 300 cal/mol. Powder X-ray diffraction peaks high-temperature phase, as well low-temperature were characterized monoclinic unit cell. Thermal also confirmed by temperature dependence lattice parameter. cell volume 0.5% smaller than that 1,400 C.