Preparation, electronic structure and thermal properties of Zn-doped LaMgAl11O19 materials

LaMgAl11O19 (LMA) with magnetoplumbite structure is a promising thermal barrier material due to its excellent thermal properties. In this work, Zn-doped LMA materials were studied in order to improve the thermal performance, and LaZnxMg1-xAl11O19 (x = 0, 0.1, 0.3, 0.5, 0.7, 1.0) were prepared by sol-gel method. The as-synthesized powder materials possess pure LMA phase and show the morphology of hexagonal plates. X-ray photoelectron spectroscopy result shows that there are AlO4 tetrahedra and AlO6 octahedra units in the target materials, and Zn2+ ions replace Mg2+ ions to occupy the tetrahedral position of magnetoplumbite structure. The composition LaZn0.3Mg0.7Al11O19 material exhibits the lowest thermal conductivity of 0.38 W/(m·K) at 1000oC while maintaining a high coefficient of thermal expansion (10.86 × 10−6 K−1). Therefore, the thermal properties of LMA materials can be improved by adding an appropriate amount of Zn ions. •LaZnxMg1-xAl11O19 (x = 0–1.0) were prepared by sol-gel method.•Electronic structure of Zn-doped LaMgAl11O19 materials were studied by X-ray photoelectron spectroscopy.•Zn doping has greatly effect on the thermal performance of the LaMgAl11O19.•LaZn0.3Mg0.7Al11O19 material exhibits the lowest thermal conductivity of 0.38 W/(m·K) at 1000oC.