Magnetic anisotropy in epitaxial CrO2 (100) thin films

CrO2 thin films fabricated on single crystal TiO2 (100) substrates by vapor phase transport grow with strongly textured growth characteristics and strong preferential orientation of the crystallites. We have used magneto-optical Kerr effect (MOKE) and alternating gradient force magnetometry (AGFM) to study the in-plane magnetic anisotropy. Both the coercive field, HC, and remnant magnetization Mr/Ms show strong twofold in-plane symmetry and the results, vs. angle, fit a coherent rotation model of domain reversal. We verify that the magnetic easy axis is along the c-axis of the crystal and the first order anisotropy constant, K1, is estimated to be about (2.3±0.2)×105 erg/cm3, consistent with the previous results. Near Tc, there are strong indications that the contributions to the magnetic anisotropy are strongly altered.