gallium oxide powder (Alfa Aesar) was calcined in a furnace at 720 °C in air for 2 hours to ensure phase transformation of α-gallia to β-gallia. Then, 𝛽-gallia was mixed with 8YSZ powder (Tosoh) in a weight ratio of 7: 3, followed by wet milling in ethanol for 5 hours at 300 rpm in a planetary ball mill (Fritsch Pulverisette) using yttriastabilized zirconia media (MSE supplies). The slurry was collected and dried overnight at room temperature in air and dried in an oven at 100 °C (Fisher Scientific) for 10 hours. The powder was sieved #70 (ASTME11) and pelletized using a stainless-steel die and a uniaxial hydraulic press (Carver) at 110 MPa, followed by cold isostatic pressing (Autoclave Engineers) at 250 MPa.