Anomalous Hall effect in anatase Ti1-xCoxO2 at low temperature regime

TL;DR

This study investigates the anomalous Hall effect in anatase Ti1-xCoxO2 thin films across a temperature range, revealing charge scattering's influence and a scaling law similar to other polymorphs, indicating a common underlying mechanism.

Contribution

It demonstrates that charge scattering significantly influences the AHE and identifies a universal scaling law in anatase Ti1-xCoxO2, comparable to rutile polymorphs.

Findings

AHE correlates with magnetization but decreases at low temperatures.

Anomalous Hall conductivity scales with the square of Hall mobility.

AHE follows a sigma_xx^1.6 scaling law, similar to rutile Ti1-xCoxO2.

Abstract

Anomalous Hall effect (AHE) of a ferromagnetic semiconductor anatase \cotio thin film is studied from 10K to 300K. Magnetic field dependence of anomalous Hall resistance is coincident with that of magnetization, while the anomalous Hall resistance decreases at low temperature in spite of nearly temperature-independent magnetization. Anomalous Hall conductivity sigma_AHE is found to be proportional to the square of Hall mobility, suggesting that charge scattering strongly affects the AHE in this system. The anatase Ti1-xCoxO2 also follows a scaling relationship to conductivity sigma_xx as sigma_AHE ~ sigma_xx^1.6, which was observed for another polymorph rutile Ti1-xCoxO2, suggesting an identical mechanism of their AHE.