Hyperfine Magnetic Fields at ¹⁸¹Ta Impurity Nuclei in Ferromagnetic ZrZn₂

Abstract

<p>The hyperfine magnetic field at ¹⁸¹Tm nuclei substituting at the zirconium sites in ferromagnetic ZrZn₂ was measured by the method of time-differential perturbed angular correlations (TDPAC). The value obtained was -17.3 ± 0.3 k0e with 2% hafnium impurity at the zirconium sites.</p> <p>The hyperfine field was also measured as a function of hafnium and titanium concentration (substituting at zirconium sites) and compared with magnetization measurements on the same samples. The magnetization data agreed qualitatively with measurements by Ogawa: the magnetization decreases to zero at about 15% hafnium concentration, but increases to a maximum at about 20% titanium concentration. The hyperfine field, however, decreases less rapidly with hafnium concentration but drops off fairly suddenly near 20% hafnium. When titanium impurity is added, the hyperfine field does not increase by as great a fraction as does the magnetization.</p>