Thermal and mechanical properties of Yb&Mg co-doped InFeZnO₄

In_0.4Yb_0.6FeZnO₄ was confirmed to possess the lowest thermal conductivity in Yb-doped InFeZnO₄. To further reduce the thermal conductivity, In_0.4Yb_0.6FeZn_1-xMg_xO₄ (x = 0, 0.1, 0.2,⋯, 0.8, 0.9, 1.0) ceramics were synthesized by solid state reaction at 1300 °C for 30 h. XRD results indicated that single phase In_0.4Yb_0.6FeZn_1-xMg_xO₄ ceramics were successfully synthesized with layered YbFe₂O₄-type crystal structure in the hexagonal R3m space group. It was found that the thermal conductivity of In_0.4Yb_0.6FeZn_0.5Mg_0.5O₄ (x = 0.5) reached a minimum value of 1.13 W m^-1 K^-1 at 1000 °C. The investigations on the thermal stability, thermal expansion coefficient, abradable property and erosion wear resistance indicate that In_0.4Yb_0.6FeZn_0.5Mg_0.5O₄ ceramics are promising thermal barrier coatings.