Using half-metallic manganite interfaces to reveal insights into spintronics

Abstract

A half-metal has been defined as a material with propagating electron states atthe Fermi energy only for one of the two possible spin projections, and as suchhas been promoted as an interesting research direction for spin electronics. Thisreview details recent advances on manganite thin film research within the field ofspintronics, before presenting the structural, electronic and spin-polarized solid-statetunnelling transport studies that we have performed on heterostructures involvingLa2/3Sr1/3MnO3 thin filmsseparated by SrTiO3 barriers. These experiments demonstrate that, with a polarization of spin electrons at the Fermi level that can reach 99%, theLa2/3Sr1/3MnO3/SrTiO3 interface for all practical purposes exhibits half-metallic behaviour. We offer insight into theelectronic structure of the interface, including the electronic symmetry of any remainingspin states at the Fermi level. Finally, we present experiments that use the experimentalhalf-metallic property of manganites as tools to reveal novel features of spintronics.