Reversible thermal phase transition was observed for Y4Al2O9 at 1377°C with a hysteresis width of 78°C using differential scanning calorimetry. The enthalpy of the transition (ΔH) was about 300 cal/mol. Powder X‐ray diffraction peaks of the high‐temperature phase, as well as the peaks of the low‐temperature phase, were characterized with a monoclinic unit cell. Thermal hysteresis was also confirmed by the temperature dependence of the lattice parameter. The unit cell volume of the high‐temperature phase was 0.5% smaller than that of the low‐temperature phase at 1400°C.
|Number of pages||3|
|Journal||Journal of the American Ceramic Society|
|Publication status||Published - 1993 Sep|
ASJC Scopus subject areas
- Ceramics and Composites
- Materials Chemistry