Magnetic relaxation in uranium ferromagnetic superconductors

TL;DR

This paper develops a phenomenological theory explaining the magnetic relaxation behavior observed in uranium ferromagnetic superconductors UGe₂ and UCoGe, focusing on neutron scattering line widths influenced by uranium atom moments.

Contribution

It introduces a new phenomenological model for neutron scattering in uranium ferromagnets accounting for non-conserved uranium moments.

Findings

Line width remains finite at all temperatures except at the Curie point.

Magnetization relaxation is driven by uranium atom moments interacting with itinerant electrons.

The theory explains experimental neutron scattering data in UGe₂ and UCoGe.

Abstract

There is proposed a phenomenological theory of quasi-elastic neutron scattering in the itinerant ferromagnets UGe$_2$ and UCoGe based on their property that magnetization supported by the moments located at uranium atoms is not conserved quantity relaxing to equilibrium by the interaction with itinerant electrons subsystem. As result the line width of quasi elastic neutron scattering at $q\to 0$ acquires nonvanishing value at all temperatures but the Curie temperature.