Large positive room temperature magnetoresistance in nanogranular FeCo–Si–N thin films

Abstract

A large positive room temperature magnetoresistance (MR) up to ~30% at 50kOe was obtained in nanogranular FeCo–Si–N thin film prepared by magnetron sputtering. The quasi-linear dependence of MR on the magnetic field is observed for the fields above 20kOe. The properties of the films depend on both the nonmagnetic component volume and film thickness. To achieve high MR, a proper Si–N content and a critical film thickness are required. The large positive MR may result from the combination of geometric effect as well as spin-dependent scattering. The FeCo–Si–N films with pronounced MR and linear MR-H behavior can be good candidates for future magnetoelectric devices.