Abstract
The transition to a charge and orbital ordered (CO/OO) state in epitaxial manganite films is strongly influenced by lattice strain. Bi1-xCaxMnO3 is a particularly interesting material due to its high transition temperature and its relation to other Bi-based materials. Here we review its properties and show the effects of strain and strain symmetry on Bi�0.4Ca0.6MnO3 films on SrTiO3 and LaAlO3 substrates with (pseudocubic) (001) and (011) orientations. Transport and magnetization data are compared to 4-circle x-ray diffraction and high-resolution Z-contrast scanning transmission microscopy data. We observe the spontaneous formation of single-unit-cell thick, Bi-rich layers only on (001) SrTiO3 substrates and different defect structures depending on the substrate type and orientation. This shows that the details of epitaxial strain play a role not only at phase transitions, but also during the growth of these materials. Results are compared to those published for other CO/OO manganite films.
