Transition to linear domain walls in nano-constrictions

TL;DR

This paper studies the thermal properties of domain walls in nano-constrictions, revealing a phase transition in the perpendicular magnetization component that depends on the domain wall width, with implications for nano-scale magneto-resistive devices.

Contribution

It introduces an analysis of thermal phase transitions in ultra-narrow domain walls using analytical, mean-field, and Monte Carlo methods, focusing on nano-constrictions.

Findings

Perpendicular magnetization component exhibits a phase transition below Curie temperature.

The effect is more pronounced in narrower domain walls.

Results are relevant for understanding magneto-resistive effects in nano-scale devices.

Abstract

Domain walls in nano-constrictions are investigated with a focus on thermal properties. In general, the magnetization component perpendicular to the easy axis which in a domain wall usually occurs has a value different from the easy-axis bulk magnetization value with a separate phase transition at a critical temperature below the Curie temperature. Since this effect is the more pronounced the smaller the domain wall width is we investigate it especially in domain walls with a confined geometry, using analytical arguments, mean-field theory and Monte Carlo simulations. Our findings may contribute to the understanding of magneto-resistive effects in domain walls with sizes of only a few atomic layers, as e. g. in nano-contacts or nano-constrictions.