TDPAC MEASUREMENTS IN TEXTURED HCP SAMPLES

Time differential perturbed angular correlation measurements done on t he 482keV level of Ta-181 probe nuclei in well annealed reference foil samples of alpha-<(Zr)under bar Hf>, alpha-<(Ti)under bar Hf> and alp ha-Hf indicate that all probe nuclei are defect free, substitutional a nd experience quadrupole frequencies characteristic of these matrices. But mostly the ratio of the intensities of the harmonic components of the quadrupole frequency is never in 3:2:1, which is understood to be due to the selective orientation of microcrystallites brought out by the pre thermo-mechanical treatments on the sample. This paper illustr ates as to how texturing in general could cause ambiguities in the mea surements of the hyperfine interaction parameters of probe nuclei part icularly in hcp foil samples with or without the association of any de fects and the ways to delineate the effect of texturing.