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arXiv · 1607.06162

Experimental and DFT investigation of (Cr,Ti)3AlC2 MAX phases stability

Patrick A. Burr·Denis Horlait·William E. Lee
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Abstract

Using a synergistic combination of experimental and computational methods, we shed light on the unusual solubility of (Cr,Ti)3AlC2 MAX phase, showing that it may accommodate Cr only at very low concentrations (<2at%) or at the exact Cr/(Cr+Ti) ratio of 2/3, even when the ratio of reactants is far from this stoichiometry (1/2 < Cr/(Cr+Ti) < 5/6). In both phases Cr exclusively occupies the 4f sites, bridging carbide layers with the Al layer. Despite this, the peculiar stability of (Cr2/3Ti1/3)3AlC2 is attributed to the formation of strong, spin-polarised Cr-C bonds, which result in volume reduction and marked increase in c/a ratio.

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Patrick A. Burr, Denis Horlait, William E. Lee. 2016-08-08. Experimental and DFT investigation of (Cr,Ti)3AlC2 MAX phases stability. https://doi.org/10.1080/21663831.2016.1222598

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