Preparation and thermo-physical properties of La1-xNdxMgAl11O19 (x=0, 0.1, 0.2) ceramics

La1-xNdxMgAl11O19 (x = 0, 0.1, 0.2) ceramic powders were synthesized by chemical-coprecipitation and calcination method, and were then pressureless-sintered at 1700 degrees C for 10 h in air to fabricate dense bulk materials. La1-xNdxMgAl11O19 ceramics were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The thermal expansion coefficients (TECs) and thermal diffusivity coefficients of La1-xNdxMgAl11O19 ceramics were studied with a high-temperature dilatometer and a laser flash diffusivity technique from room temperature up to 1200 degrees C. La1-xNdxMgAl11O19 (x = 0, 0.1, 0.2) ceramics exhibited a defect magnetoplumbite structure. The TECs of LaMgAl11O19 and La0.8Nd0.2MgAl11O19 are 8.49 x 10(-6) K-1 and 8.58 x 10(-6) K-1 at 1200 degrees C. respectively. The thermal conductivity of La1-xNdxMgAl11O19 (x = 0, 0.1, 0.2) ceramics locates in the range of 2.62-3.87 W m(-1) K-1 from room temperature to 1200 degrees C (C) 2009 Elsevier B.V. All rights reserved.