Two Intermediate States in Exchange Biased [Co/Pt]2/Co layers and Possible Applications of These States

Abstract

Two intermediate states in the [Co(1.0 nm)/Pt(tPt)/]2/Co(1.0 nm)/IrMn(12.0 nm) multilayer are investigated as a function of the Pt layer thickness, tPt. Ferromagnetic coupling between the Co layers was dominant when the Pt layer thickness was smaller than 1.6 nm. Because of the exchange bias from IrMn layer and interlayer coupling between the Co layers, symmetric magnetization curves with two intermediate state are revealed when the Pt layer is thicker than 2.0 nm. The spin configurations of the intermediate states are demonstrated by measuring the extraordinary Hall effect and magnetoresistance changes depending on the external magnetic field. We will discuss the details of the structures and the measurements and give possible applications, such as memory, logic, and switching devices.