Cold-pressed alpha-Ta4AlC3 powders were annealed up to 1750 degrees C to test first-principles predictions of alpha-beta phase-stability reversal at 1600 degrees C. Up to 1600 degrees C, the alpha-Ta4AlC3 samples were stable with no indications of any alpha-beta transformation, as shown by the strong characteristic X-ray diffraction peaks of alpha-Ta4AlC3 and the zigzag stacking observed by transmission electron microscopy. These results show that, in this experimental situation, high temperature alone is not sufficient to cause the alpha-beta transformation. (C) 2011 Elsevier Ltd. All rights reserved.