Study on the hyperfine interactions of 181Ta nuclei in YFe3 intermetallide by the perturbed angular γγ correlation method

By the method of the pertubed angular correlation (PAC) hyperfine inteactions in sup(181)Ta nuclei produced from sup(181)Hf β-decay in YFe3 ferromagnetic intermetallic compound are investigated. One of the aims of the study is refinement of sup(181)Ta nucleus magnetic moment in the first rotational state of the fundamental band: E=136.25 keV, Isup(π)=9/2sup(+), Tsub(1/2)=40 nc. In the YFe3 sample about 1% of Y atoms have been substituted by Hf atoms which have been activated by sample irradiation in the reactor. Then the sample has been annealed in vacuum at 900 deg C. For the determination of electric quadrupole interaction constants measurements of differential by time PAC with the source heated above the curve point and at room temperature are performed. The analysis has shown that the best description of spectra is obtained under the assumption of two nonequivalent positions of experimental atoms. The numerical spectrum analysis revealed the precession frequency corresponding to the hyperfine field value - Bsub(hf)=18.5(2.0) Tl