Method of preparation and thermodynamic properties of transparent Y3Al5O12 nanoceramics

We first introduce the latest experimental results, i.e., production of the fine nanostructured and near fully dense transparent Y₃Al₅O₁₂ (YAG) bulks at high pressure and modest temperature (2.0–5.0 GPa and 300–500 °C). And then, we employ the first-principles plane wave pseudopotential density functional theory method to calculate the equilibrium lattice parameters and the thermodynamic properties of YAG. The obtained lattice parameters are consistent with the experimental data and the available theoretical data of others. Through the quasi-harmonic Debye model, the dependences of the normalized primitive volume V/V ₀ on pressure P, the Debye temperature $ Uptheta_{rm{D}} $ , and the heat capacity C _V on pressure P and temperature T, as well as the variation of the thermal expansion α with temperature and pressure are obtained successfully.