Localization of 5f-electrons and pressure effects on magnetism in U intermetallics in the light of spin-fluctuation theory

TL;DR

This study uses spin-fluctuation theory to analyze how 5f-electron localization influences pressure effects on magnetism in uranium intermetallics, explaining contrasting behaviors in similar compounds.

Contribution

It applies Takahashi's spin-fluctuation theory to uranium intermetallics, linking 5f-electron localization to pressure-dependent magnetic properties.

Findings

Determined spin-fluctuation parameters T0 and TA for UCoGa and URhGa.

Identified correlations between 5f-electron localization and Curie temperature response.

Proposed broader applicability of the localization-magnetism relationship in uranium compounds.

Abstract

UCoGa and URhGa, two isostructural compounds show opposite signs of the initial response of Curie temperature to applied hydrostatic premenssure. To determine the physical origin of this contradiction the magnetization data measured with respect to temperature, magnetic field and hydrostatic pressure were analyzed in the framework of the Takahashi's spin-fluctuation theory. The parameters T0 and TA characterizing the distribution widths of the spin-fluctuation spectrum in the energy and wave vector space, respectively, and TC/T0, the degree of the 5f-electron localization have been determined. Examination of available experimental data for the other UTX (T = a transition metal, X = Al, Ga) ferromagnets having the ZrNiAl-type structure revealed some correlations between the degree of the 5f-electron localization represented by the spin-fluctuation parameters and the response of Curie-temperature on the applied pressure. These observations may be applied more generally to describe the localization and magnetic behaviors of the majority of the uranium ferromagnetic compounds.