Emergent Magnetic Phenomenon with Unconventional Structure in Epitaxial Manganate Thin Films

A variety of emergent phenomena has been enabled by interface engineering in the complex oxides heterostructures. While extensive attention attracted to LaMnO3 (LMO) thin films for observing control functionalities at its with substrate, nature magnetic phases film is, however,controversial. Here, it is reported that ferromagnetism 2 and 5 unit cells thick LMO epitaxially deposited (001)-SrTiO3 substrates ferromagnetic/ferromagnetic coupling 8 10-unit-cell ones, a striking ferromagnetic/antiferromagnetic pinning effect apparent positive exchange bias 15 20-unit-cell ones are observed. This novel phenomenon both indicates coexistence three orderings single film.The high-resolution scanning transmission electron microscopy suggests P21/n Pbnm symmetry transition from surface, spatial stratification MnO6 octahedral morphology, corresponding different orderings. These results should shed some new lights on manipulating functionality engineering.