Barkhausen-type noise in the resistance of antiferromagnetic Cr thin films

TL;DR

This study investigates resistance noise in Cr thin films linked to spin density wave domain transformations, drawing an analogy with Barkhausen noise in ferromagnets and proposing a generalized Preisach model.

Contribution

It introduces a novel analogy between resistance noise in antiferromagnetic Cr films and Barkhausen noise, along with a generalized hysteron-based model for domain dynamics.

Findings

Resistance noise appears within hysteretic temperature regions.

The noise is explained by a model of resistive hysterons.

Domain distributions influence the observed resistance fluctuations.

Abstract

We present an experimental study of the changes generated on the electrical resistance $R(T)$ of epitaxial Cr thin films by the transformation of quantized spin density wave domains as the temperature is changed. A characteristic resistance noise appears only within the same temperature region where a cooling-warming cycle in $R(T)$ displays hysteretic behavior. We propose an analysis based on an analogy with the Barkhausen noise seen in ferromagnets. There fluctuations in the magnetization $M(H)$ occur when the magnetic field $H$ is swept. By mapping $M \rightarrow \Psi_0$ and $H \rightarrow T$, where $\Psi_0$ corresponds to the order parameter of the spin density wave, we generalize the Preisach model in terms of a random distribution of {\it resistive hysterons} to explain our results. These hysterons are related to distributions of quantized spin density wave domains with different sizes, local energies and number of nodes.