Tailoring colossal magnetoresistance and magnetoresistive memory effect by two-dimension-like phase competition in electron-doped manganite superlattices

Abstract

Colossal magnetoresistance and giant magnetoresistive memory effect have been demonstrated in the electron-doped manganite superlattices composed of alternatively of G-type antiferromagnetic insulator (G-AFI) layers of CaMnO 3 and C-type antiferromagnetic insulator (C-AFI) layers of Ca 0.92 Ce 0.08 MnO 3 . The transport properties of the superlattices strongly depend on the periodicity and the unit cells of each layer. The charge transfer through the interface of the constituent insulators induces appearance of the canted G-type antiferromagnetic metal (cG-AFM) phase in the superlattices. Enhanced colossal magnetoresistance and memory effect emerge in the superlattices composed of the thinner G-AFI layers, which can be attributed to the artificially generated two-dimension-like phase competition between cG-AFM and C-AFI in the charge transfer region. The effective charge transfer through interface provides us an opportunity to control phase separation and thus tailoring electronic properties of electron-doped manganites.

Current-dependent positive magnetoresistance in La0.8Ba0.2MnO3 ultrathin films*

“…In recent decades, the colossal magnetoresistive (CMR) effect in perovskite manganites has attracted extensive attention because of its potential application in magnetic recording and sensors. [1][2][3] It has also been widely recognized that the double-exchange interaction between Mn 3+/4+ ions is a key mechanism that is responsible for the significant decrease of the electrical resistance under a magnetic field at temperatures around the magnetic phase transition. [4] However, in manganites, a positive magnetoresistive (PMR) effect, i.e., a magnetic-field-induced increase of resistance, has not been reported as frequently as colossal magnetoresistance.…”