Thermal explosion synthesis of first Te-containing layered ternary Hf2TeB MAX phase

With the new discovery of layered boride compounds M2AB (M = Zr, Hf, Nb; A = S, Se) with the typical Cr2AlC-type structure, MAX phases have been successfully expanded from carbides and nitrides to borides. However, only five MAX phase borides have been synthesized at present, which means that the research on MAX phase borides is still in its infancy. Therefore, the exploration of new MAX phase borides is necessary and can provide a solid basis for future research. In this paper, we describe the discovery of the first tellurium (Te)-containing layered ternary compound Hf2TeB using combinatorial methods of thermal explosion synthesis, XRD, SEM, and HRTEM analyses. This new MAX phase crystallizes with a Cr2AlC-type structure with the space group of P63/mmc, and the lattice parameters are a = 3.60475 Å, c = 13.12663 Å, respectively, and atomic positions are Hf at (1/3, 2/3, 0.57505), Te at (1/3, 2/3, 1/4), and B at (0, 0, 0).