Fe Hyperfine Fields in Dilute Pd–Fe Alloys

Abstract

We have studied the 57Fe hyperfine field distribution in an alloy of 0.5 at. % Fe in Pd by NMR spin-echo spectroscopy at temperatures between 1.3° and 4.2°K. The Fe spectrum at 4.2°K is asymmetric. The asymmetry decreases and the frequency of the maximum increases as the temperature is lowered so that at the lowest temperature the Fe line is essentially symmetric about a value corresponding to a field of −299.7 kOe. The interpretation of this data in terms of an enhanced RKKY spin polarization model is presented. The temperature dependence of the maximum is fitted to a T3/2 law and a value of 34°K Å2 for the acoustic spin-wave stiffness constant in this alloy is obtained.