Evidence of ZnCO3 interstitial phase in carbon implanted ZnO(002) thin films and room temperature ferromagnetism

High resolution X-ray diffraction (HRXRD) pattern of highly c-oriented (002) thin film provide a direct evidence of the formation of R-3c orthorhombic ZnCO3 structural phase. Room temperature ferromagnetism (RTFM) is measured using bulk vibrating sample magnetometery (VSM). A strong orbital anisotropy has been observed by X-ray linear dichmism (XLD) experiment, which also supports that ZnCO3 phase is structurally non-distortive after carbon-implantation. The absence of X-ray magnetic circular dichmism (XMCD) signal at O K- and C K-edges suggest that bulk VSM ferromagnetism is not related to the magnetic polarization of O 2p/C 2p orbitals hybridized with Zn-states. These experiments clearly indicate that the complex C-ZnO/ZnCO3 phase should be ferromagnetic having out-of-plane/in-plane orbital reconstruction.

Automated summary

The experimental results indicate that the ZnCO3 phase after carbon implantation is structurally non-distortive with orbital anisotropy, supported by XLD experiment. Additionally, the absence of XMCD signal at O K- and C K-edges further confirms that bulk VSM ferromagnetism is not related to the magnetic polarization of O 2p/C 2p orbitals.