Resurrected and Tunable Conductivity and Ferromagnetism in the Secondary Growth La_0.7Ca_0.3MnO₃ on Transferred SrTiO₃ Membranes

To avoid the epitaxy dilemma in various thin films, such as complex oxide, silicon, organic, metal/alloy, etc., their stacking at an atomic level and secondary growth are highly desired to maximize the functionality of a promising electronic device. The ceramic nature of complex oxides and the demand for accurate and long-range-ordered stoichiometry face severe challenges. Here, the transport and magnetic properties of the La_0.7Ca_0.3MnO₃ (LCMO) secondary growth on single-crystal freestanding SrTiO₃ (STO) membranes are demonstrated. It has been experimentally found that on an only 10 nm thick STO membrane, the LCMO can offer a bulk-like Curie temperature (T_C) of 253 K and negative magnetoresistance of −64%, with a weak dependence on the thickness. The resurrected conductivity and ferromagnetism in LCMO confirm the advantages of secondary growth, which benefits from the excellent flexibility and transferability. Additionally, this study explores the integration strategy of complex oxides with other functional materials.