An investigation of phase stability, thermal conductivity and fracture toughness of 8YSZ-La2O3 ceramics

La2O3-8YSZ composite ceramics were fabricated by using conventional sintering (1400 °C/5 h). Scanning electron microscopy studies revealed bimodal microstructure, consisting of YSZ and La2Zr2O7 phases. The resultant ceramic composite was fully stabilized in cubic crystal structure. The thermal conductivities achieved in the La2O3-8YSZ samples were lower than pure 8YSZ. The fracture toughness of 8YSZ decreases with the La2O3 addition.