Progress in Zno-based diluted magnetic semiconductors

ZnO-based diluted magnetic semiconductors (DMS) have attracted a great deal of research attention and controversy over the past decade. The initial attention was sparked by the prediction of above-room-temperature ferromagnetism in Mn-doped ZnO by T. Dietl. This was followed by a surge of reports of ferromagnetism in thin film transition metal (TM)-doped ZnO. However, reported values of magnetic moments and Curie temperatures were inconsistent, which led to controversy over the origin of the observed ferromagnetism. In this paper we review a number of TM-doped ZnO-based DMS in order to clarify which materials are likely ferromagnetic.