Total Thermal Expansion Coefficients of the Yttrium Silicate Apatite Phase Y4.69(SiO4)3O

The formation of the Y4.69(SiO4)3O apatite phase was observed in compositions targeted at the yttrium monosilicate and disilicate phases. Through the use of high-temperature in situ X-ray diffraction, the lattice parameters of the phase were characterized as a function of temperature, and thermal expansion coefficients were calculated. Phase fractions were assessed as a function of sintering temperature, and the apatite phase fraction increased with temperature.