Magnetocapacitance of La1−xCaxMnO3/SrTiO3: Nb junctions with different Ca contents

Manganite-based heterojunctions La1−xCaxMnO3/SrTiO3: Nb (0.5 wt. %) with x = 0.2, 0.3, 0.375, 0.4, 0.5, 0.6, and 0.7 have been fabricated, and the lattice constants of La1−xCaxMnO3 films are experimentally studied. The capacitance characteristics of those junctions under a magnetic field have been investigated. Obvious magnetocapacitance was observed in La0.7Ca0.3MnO3/Nb-SrTiO3 p-n junction near the Curie temperature (TC) of La0.7Ca0.3MnO3 at 0.75 T. The result can be explained by phase separation. This study demonstrates the remarkable tunability of the capacitance for phase separated manganite heterojunctions, which may lead to some potential applications.