Synthesis of lanthanum zirconium oxide nanomaterials through composite-hydroxide-mediated approach

A novel thermal barrier coating material, lanthanum zirconium oxide (La(2)Zr(2)O(7)) has been synthesized through the composite-hydroxide-mediated method at low temperature. The phase structures, morphology, thermal stability and thermal conductivity of the as-synthesized La(2)Zr(2)O(7) were investigated systematically. The X-ray diffraction (XRD) patterns revealed a single phase with cubic pyrochlore structure for La(2)Zr(2)O(7) after treated at 1300 degrees C for 100 h. The transmission electron microscope (TEM) and scanning electron microscope (SEM) analyses showed that the sample was made up of sphere-like nanoparticles with the size between 50 and 100 nm. Furthermore, the thermal analysis result demonstrated the La(2)Zr(2)O(7) sample had high thermal stability even at 1300 degrees C. As the temperature increased to 1200 degrees C, the thermal conductivity value could be as low as 1.75 W m(-1) K(-1). Due to the high-temperature stability and lower thermal conductivity, the La(2)Zr(2)O(7) material is expected to be a promising candidate for the use of thermal barrier coatings. (C) 2011 Elsevier Ltd. All rights reserved.