Experimental investigation of the metastable magnetic properties of Cr-doped InN

We have performed detailed time-, field-, and temperature-dependent magnetic measurements on Cr-doped InN films, a dilute magnetic semiconductor (DMS) material which exhibits long range magnetic order above room temperature. We find a metastable magnetic behavior rather than common ferromagnetism. The temperature dependence of the remanence is not reversible with temperature and can be increased at a given temperature between 250 and 400 K by applying an external magnetic field. The field dependence of this effect qualitatively follows the magnetic hysteresis with a saturation field around 1.3-1.5 T. The remanence is stable on a time scale of many hours but may decay on a time scale of days. This metastable magnetic behavior may be interesting for applications as well as theoretical efforts to better understand the origin of the magnetic order in such DMS systems. © 2007 The American Physical Society.