Experimental and ab initio study of the electric field gradients at Ta and Cd impurities in TiAl3

The hyperfine quadrupole interaction parameters and their temperature dependence for 181Hf/181Ta probe in TiAl3 compound were determined using the time differential perturbed angular correlation (TDPAC) method. In addition, ab initio calculations using the augmented plane wave plus local orbitals (APW + lo) method as implemented in the WIEN2k code, within the framework of the density functional theory (DFT) have been performed. Through the comparison of the calculated and measured electric field gradients (EFG) it was established that Ta occupies Ti 2(a) position, while Cd probe is settled at the Al 4(d) site.