Surface and grain-boundary energies of cubic zirconia

Using the multiphase equilibration technique for the measurement of contact angles, the surface and grain-boundary energies of polycrystalline cubic ZrO₂ in the temperature range of 1173 to 1523 K were determined. The temperature coefficients of the linear temperature function obtained, are expressed as $$frac{{{text{d}}gamma }}{{{text{d}}T}}({text{ZrO}}_{text{2}} ){text{ }} = {text{ }} - 0.431{text{ }} times {text{ }}10^{ - 3} {text{ }} pm {text{ }}0.004{text{ }} times {text{ }}10^{ - 3} {text{ Jm}}^{ - {text{2}}} {text{ K}}^{ - {text{1}}} $$ and $$frac{{{text{d}}gamma }}{{{text{d}}T}}({text{ZrO}}_{text{2}} - {text{ZrO}}_{text{2}} ){text{ }} = {text{ }} - 0.392{text{ }} times {text{ }}10^{ - 3} {text{ }} pm {text{ }}0.126{text{ }} times {text{ }}10^{ - 3} {text{ Jm}}^{ - {text{2}}} {text{ K}}^{ - {text{1}}} $$ respectively. The surface fracture energy obtained with a Vickers microhardness indenter at room temperature is found to be γ _F=3.1 J m^?2.