SELENIUM PRECIPITATION IN ZNSE CRYSTALS GROWN BY PHYSICAL VAPOR TRANSPORT

The morphology of freshly cleaved ZnSe surfaces was investigated by at omic force microscopy and the results were correlated with differentia l scanning calorimetry (DSC) data. Selenium precipitates in undoped Zn Se crystals grown by the physical vapor transport method were determin ed. The Se inclusions have a size of about 20 nm. A transition tempera ture at 221 degrees C in the DSC measurement is interpreted as the eut ectic temperature of Se-saturated ZnSe. The total amount of the ZnSe/S e-rich second phase was 0.8 wt%, and some segregation effect along low angle grain boundaries was evident.