Defect engineering of room‐temperature ferromagnetism of carbon‐doped ZnO

Abstract

Abstract This study investigates the role of carbon (C) in room‐temperature (RT) ferromagnetic C:ZnO films. RT ferromagnetism can be observed in air‐annealed C:ZnO samples. However, no feature that could be attributed to the incorporation of carbon at O sites (C O ) was observed. An analysis of MCD spectra of the ferromagnetic C:ZnO sample included a non‐ferromagnetic peak and a ferromagnetic one. These are related to the loss of carbon and the creation of defects in an air‐annealed C:ZnO film by the reaction between C dopants and oxygen. We suggest even if the C dopants are not at C O sites, C is still a novel dopant to make ZnO ferromagnetic in controlling the defects in the structure formed by suitable post‐annealing. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)