Metastable (Zn1-xMgx)O alloy films having a MgO fraction (x = 0.47) in excess of the solubility limit (x ≈ 0.15) were studied. The residual electron concentrations in the metastable films were close to those of stable films having a lower MgO fraction (x = 0.07). In contrast to the electrical conductivity, the diffusivities of both cations and anions in the metastable films were surprisingly higher than those in the stable films. This indicated that a high concentration of compensated defects was generated in metastable alloy with a high MgO fraction. Photo-emission spectroscopy confirmed the presence of ionized acceptors for charge compensation in the metastable (Zn1-xMgx)O.

Formation of Compensated Defects in Zinc Magnesium Oxides Assignable from Diffusion Coefficients and Hard X-ray Photoemission. Ohsawa, T., Sakaguchi, I., Ohashi, N., Haneda, H., Ryoken, H., Matsumoto, K., Hishita, S., Adachi, Y., Ueda, S., Yoshikawa, H., Kobayashi, K.: Applied Physics Letters, 2009, 94[4], 042104