Probing magnetic anisotropy effects in epitaxialCrO2thin films

The magnetic anisotropy in ferromagnetic chromium dioxide thin films ${(T}_c\sim 393\mathrm{K})$ grown epitaxially on (100) ${\mathrm{TiO}}_2$ substrates, is probed using precise rf transverse susceptibility $\left({\chi }_T\right)$ measurements. Singular peaks in ${\chi }_T$ are observed that are associated with the anisotropy $(\pm H_K)$ and switching $(\pm H_s)$ fields in ${\mathrm{CrO}}_2.$ Theoretical calculations of ${\chi }_T$ based on a simple coherent rotation model display remarkable agreement with the experimental data, indicating that these thin films behave like single-domain magnetic particles. Magnetoelastic contributions to the total anisotropy energy are needed to describe the evolution of ${\chi }_T$ peaks at lower temperatures.