Sign and magnitude of the magnetic hyperfine field suggest the existence of a localized moment of about −0.4 µ B at the site of Os in Gd.

Time differential perturbed angular correlation spectra of111Cd in ferromagnetic polycrystalline Dy have been measured at 4.2 K in external magnetic fields up to 60 kG. The experimental data were well reproduced by a calculation which assumed that the angular distribution of the magnetic hyperfine fields is identical to that of the magnetic moments of the 4f-shells. The distribution of the 4f-moments was derived from magnetic anisotropy data. The results of this work seem to justify the application of the integral perturbed angular correlation technique for the determination of magnetic hyperfine fields in incompletely polarized ferromagnetic samples. The magnetic hyperfine fields of177Hf:Gd and177Hf:Dy have been measured by this method as:Hhf(Hf:Gd)=−375(60)kG andHhf(Hf:Dy)=−225(45)kG.

Measurements of nuclear-quadrupole-interaction constants in perovskite-type compounds of PbHf${\mathrm{O}}_{3}$, SnHf${\mathrm{O}}_{3}$, CaHf${\mathrm{O}}_{3}$, and SrHf${\mathrm{O}}_{3}$ have been performed using the perturbed-angular-correlation technique. A range of fundamental frequencies from 150\ifmmode\times\else\texttimes\fi{}${10}^{6}$ to 550\ifmmode\times\else\texttimes\fi{}${10}^{6}$ rad/sec was determined. The variation of the quadrupole constants has been discussed through the molecular-orbital theory. A semiempirical formula for the admixture coefficient between $d$ wave functions and $p$ wave functions which describes the covalent bonding present in each $\mathrm{AB}{\mathrm{O}}_{3}$ compound has been derived.

Fourier analysis is applied to the study of perturbed angular correlation time spectra. The effects of a finite measuring interval, discrete measuring points, statistical fluctuations, and nuclear relaxation on the Fourier spectra are shown using simulated time spectra. The effects of finite time resolution on the time spectra are reviewed and a method for partially removing them using Fourier techniques is presented.