Thermal Expansion and Athermal Phase Transition of Y4AI2O9 Ceramics

摘要: Thermal Expansion of Y{sub 4}Al{sub 2}O{sub 9} ceramics prepared at 1,600 and 1,800 C was measured from room temperature to 1,500 in air. Volume changes the phase transition 9}, along with thermal hysteresis, were observed around 1,400 C. The volume high-temperature about 0.5% lower than that low-temperature phase. hysteresis width for sample 56 C, wider (14 C) averages start temperatures on heating cooling these samples were, however, almost same 1,377 transitions did not occur fixed temperatures, proportions change time as long remained constant (athermal character). also showed another behavior 1,000