Internal Magnetic Fields at Pt Nuclei in Pt-Fe Alloys

Abstract

The Mössbauer effect of the 99-keV, ${\frac{3}{2}}^{-}$-to-${\mathrm{½}}^{-}$ transition in ${\mathrm{Pt}}^{195}$ has been measured, using a single-line source of ${\mathrm{Au}}^{195}$ in Cu and ferromagnetic Fe-Pt alloy absorbers. The internal field at the Pt nucleus, $H_{\mathrm{int}}\left(\mathrm{Pt}\right)$, in the alloy absorbers was determined and found to be nearly constant, about 1.26×${10}^6$ Oe, over a range of composition from 3 to 30 at.% Pt. $H_{\mathrm{int}}\left(\mathrm{Pt}\right)$ for an ${\mathrm{Fe}}_{0.50}$ ${\mathrm{Pt}}_{0.50}$ alloy absorber and for a source (${\mathrm{Au}}^{195}$→${\mathrm{Pt}}^{195}$ in Fe) are smaller, $H_{\mathrm{int}}\left(\mathrm{Pt}\right)\simeq 1.0\times {10}^6 \mathrm{and} 0.85\times {10}^6$ Oe, respectively. The $g$ factor of the state is found to be -0.40±0.10 nm.