PERTURBED-ANGULAR-CORRELATION MEASUREMENTS AT TA-181 IN HF2PD AND ZR2PD TETRAGONAL MOSI2-TYPE PHASES

The electric quadrupole interaction at Ta-181 in Hf2Pd and Zr2Pd compo unds was studied by the perturbed angular correlation method in a broa d temperature range. The powder X-ray analysis verified a single-phase C11(b) structure of the samples. The least-squares fits of the pertur bation factor to the experimental spectra measured for Hf2Pd and Zr2Pd compounds yielded an electric interaction with a well-defined single quadrupole frequency (nu(Q)=305(2) MHz for Hf2Pd and 291(4) MHz for Zr 2Pd) and asymmetry parameter eta=0, reflecting the existence of one ax ially symmetric probe site. A decrease in the quadrupole interaction f requency with an increase of temperature is very rapid for both Hf2Pd and Zr2Pd compounds.