Magnetic dipole and electric quadrupole interactions of 181Ta probe in Ni–Hf alloy

Abstract

The hyperfine interactions of 181Ta probe in the nickel–2 at.% hafnium alloy have been studied by the perturbed angular correlation method in the temperature range 78–1131 K. The magnitude of the magnetic dipole interaction of 181Hf/ 181Ta substituting in ferromagnetic Ni(Hf) solid solution decreases with increasing temperature. As a result of the restricted solid solubility of Hf in Ni, a second phase (HfNi 5) in the Ni–Hf sample was detected. 181Hf/ 181Ta which resides in HfNi 5 senses weak electric quadrupole interaction. The observed anomalous temperature behavior was ascribed to distortions in the HfNi 5 cubic phase. The third measured hyperfine interaction corresponds to the quadrupole interaction of 181Hf/ 181Ta positioned in HfO 2 contamination originating from an annealing procedure above 900 K.