In-plain electric properties of [CaMnO3/REMO3] (RE=Bi, La M=Fe, Fe0.8Mn0.2) superlattices grown by pulsed laser deposition method

The [CaMnO3 (CMO)/REMO3] (RE = Bi, La M = Fe, Fe0.8Mn0.2) superlattices show semiconducting behavior with transition temperatures (TEg) of 71, 127, and 151 K in the [CMO/BiFe0.8Mn0.2O3], [CMO/BiFeO3], and [CMO/LaFeO3] superlattices. The formation of a magnetic polaron is expected in the CMO layer of the superlattices at TEg, where carrier density drops. A weak ferromagnetic interaction at the interface is expected at room temperature, because the sheet resistance RS and the Hall resistance Rh show a quadratic behavior and anomalous Hall effect as a function of magnetic field. The mobility also drops at the temperatures where both the ferromagnetic and antiferromagnetic interactions are expected to coexist. With decreasing temperature, the mobility is still low but stable. We consider that the electron transfer took place owing to the cation intermixing, not to the polar/nonpolar discontinuity, at the interface in the prepared superlattices.