Structural and magnetic properties of heteroepitaxial CrO₂ / TiO₂ bilayers grown on the Al₂ O₃ substrate

Heteroepitaxial CrO₂ / TiO₂ bilayers have been grown on the c-plane, the m-plane, the r-plane and the a-plane Al₂ O₃ substrates by a combined method of pulsed laser deposition and chemical vapor deposition, and their structural and magnetic properties have been studied. The (2 0 0) CrO₂ films on the c-plane showed the best out-of-plane crystallinity but a 60^{{ring operator}} twin growth within the plane. On the other hand, the (0 0 2) CrO₂ on the m-plane and the (1 0 1) CrO₂ on the r-plane and the a-plane displayed a relatively good in-plane texture. The magnetic property depending on the crystal orientation has been observed by the measurements of magnetic hysteresis loop and magnetoresistance at room temperature.