First-order Raman scattering of the MAX phases: Ti _2AlN, Ti _2AlC _(0.5)N _(0.5), Ti _2AlC, (Ti _(0.5)V _(0.5)) _2AlC, V _2AlC, Ti _3AlC _2, and Ti _3GeC _2

摘要

Here, we report, for the first time, on the Raman spectra of Ti _2AlN, Ti _2AlC _(0.5)N _(0.5), (Ti _(0.5)V _(0.5)) _2AlC, Ti _3AlC _2, and Ti _3GeC _2 and compare the results with those of Ti _2AlC and V _2AlC reported previously. The first-order mode peaks of the end members are narrower than those of their respective solid-solution compounds. The Ti _3AlC _2 and Ti _3GeC _2 phases show, in addition to atomic displacements of the 'M' and 'A' atomic planes, modes that correspond with vibrations of the 'X' sublattice relative to itself. We also predict the Raman modes using density functional theory. The agreement between theory and experiment was found to be satisfactory.