Thermal stability and crystal structure of high-temperature compound Al13CeMg6.

In order to clarify the controversy in the literature reports, we studied the thermal stability of the ternary compound Al 13 CeMg 6 by integrating X-ray powder diffraction, electron probe microanalyzer and differential scanning calorimetry techniques. It was found that the compound Al 13 CeMg 6 decomposes at a certain temperature between 320 and 400 °C with a eutectoid reaction: Al 13 CeMg 6 → Al 11 Ce 3 +Al 3 Mg 2 , and melts at 492 °C via a peritectic reaction: Liquid + Al 11 Ce 3 → Al 13 CeMg 6 . Moreover, the crystal structure of Al 13 CeMg 6 compound was successfully determined by X-ray powder diffraction using the Rietveld method. The compound crystallizes in the hexagonal, space group P 63/ mmc (No. 194) with the structure type of MgNi 2 and lattice parameters of a = 0.5525(9) and b = 1.7866(2) nm. [ABSTRACT FROM AUTHOR]