Tuning the magnetic and transport properties of La0.8Ca0.2MnO3 films by Ba0.8Sr0.2TiO3 intercalated layers grown with polymer-assisted deposition

The La0.8Ca0.2MnO3/Ba0.8Sr0.2TiO3 (LCM/BST) bilayer films were epitaxially grown on SrTiO3 substrates with different orientations by the polymer-assisted deposition. The effects of annealing atmosphere and substrate orientation on the magnetic and transport properties of LCM/BST bilayer films have been investigated. A well crystallization quality of the films is confirmed by X-ray diffraction. Besides, the resistivity of the LCM/BST bilayer film shows high substrate-orientation dependent metal-insulator transition (MIT). However, with the decrease in temperature, in addition to the MIT at ∼220 K, an additional MIT emerges at a lower temperature and becomes robust, especially for the (111)-oriented LCM/BST bilayer film. Moreover, the additional MIT still exists when annealed in O2/air atmosphere but disappears in O2 atmosphere. Corroborated by the magnetic properties, it shows that the intercalated-layer technique of tuning the physical properties of transition-metal oxide films is achievable and more vari...