Beta-NMR of Isolated Lithium in Nearly Ferromagnetic Palladium

TL;DR

This study uses beta-NMR to investigate how isolated lithium impurities behave in nearly ferromagnetic palladium, revealing temperature-dependent shifts and relaxation rates that relate to Pd's magnetic properties.

Contribution

It provides new insights into the local magnetic response of Pd to lithium impurities using beta-NMR, highlighting temperature-dependent phenomena.

Findings

The NMR shift is large, negative, and increases with decreasing temperature, following Pd's bulk susceptibility.

Below T*~100 K, an additional shift suggests Pd's response to defects.

The relaxation rate is slower than expected and linearly depends on temperature below T*.

Abstract

The temperature dependence of the frequency shift and spin-lattice relaxation rate of isolated, nonmagnetic Li-8 impurities implanted in a nearly ferromagnetic host (Pd) are measured by means of beta-detected nuclear magnetic resonance (b-NMR). The shift is negative, very large and increases monotonically with decreasing T in proportion to the bulk susceptibility of Pd for T > T*~ 100 K. Below T*, an additional shift occurs which we attribute to the response of Pd to the defect. The relaxation rate is much slower than expected for the large shift and is linear with T below T*, showing no sign of additional relaxation mechanisms associated with the defect.