Multi-domained heteroepitaxial rutile-phase TiO
2 (1 0 0)-oriented films were grown on Si (1 0 0) substrates by using a 30-nm-thick BaF
2 (1 1 1) buffer layer at the TiO
2–Si interface. The 50 nm TiO
2 films were grown by electron cyclotron resonance oxygen plasma-assisted electron beam evaporation of a titanium source, and the growth temperature was varied from 300 to 600 °C. At an optimal temperature of 500 °C, X-ray diffraction measurements show that rutile phase TiO
2 films are produced. Pole figure analysis indicates that the TiO
2 layer follows the symmetry of the BaF
2 surface mesh, and consists of six (1 0 0)-oriented domains separated by 30° in-plane rotations about the TiO
2 [1 0 0] axis. The in-plane alignment between the TiO
2 and BaF
2 films is oriented as [0 0 1] TiO
2 || BaF
2 or [0 0 1] TiO
2 || BaF
2 . Rocking curve and STM analyses suggest that the TiO
2 films are more finely grained than the BaF
2 film. STM imaging also reveals that the TiO
2 surface has morphological features consistent with the BaF
2 surface mesh symmetry. One of the optimally grown TiO
2 (1 0 0) films was used to template a CrO
2 (1 0 0) film which was grown via chemical vapor deposition. Point contact Andreev reflection measurements indicate that the CrO
2 film was approximately 70% spin polarized.
相似文献