Dependence of the magnetic properties on the Cr content in ZnCrO thin films

We investigated the effect of the Cr content on the magnetic properties of ZnCrO thin films (Cr: 1.0 - 12.5 at.%). Regardless of the Cr concentration, all of the films exhibited clear ferromagnetism even at temperatures above 350 K. For the dependence of spontaneous magnetization on the Cr concentration, however, the magnitude of effective magnetic moment (per Cr ion) was observed to exponentially decrease with increasing Cr content. We attributed the decreased spontaneous magnetization to the degraded crystal magnetic anisotropy. Namely, we found that, in a magnetic-ion-doped thin film, the high concentration of magnetic ions caused a lattice distortion and consequently degraded the ferromagnetic channeling in the solid-state material system.