Persisting correlation between electrical transport and magnetic dynamics in M-type hexaferrites

TL;DR

This study reveals a persistent correlation between electrical transport and magnetic dynamics in hexaferrites, suggesting a common relaxational mechanism influenced by charge carriers across various compositions.

Contribution

It demonstrates a consistent link between electric transport activation energies and magnetic susceptibility across different aluminium substitutions in hexaferrites.

Findings

Correlation between activation energies and magnetic susceptibility persists across compositions.

Charge carriers influence magnetic domain wall pinning and dynamics.

A general relaxational mechanism affects ferrimagnetic semiconductors.

Abstract

In this work we present frequency-dependent magnetic susceptibility and dc electric transport properties of three different compositions of hexaferrite Ba$_{1-x}$Pb$_{x}$Fe$_{12-y}$Al$_{y}$O$_{19}$. We find a correlation between activation energies of dc electric transport and ac magnetic susceptibility which persists in the whole researched range of aluminium substitution $x=0$ to $3.3$. This result is discussed in the context of charged magnetic domain walls, the pinning of which is determined by charge carriers activated over the transport gap. Our work points toward a general relaxational mechanism in ferrimagnetic semiconductors which directly affects dynamic magnetic properties via electric transport.