Electron-irradiation studies of vapour-grown ZnO ribbon crystals were carried out in situ in a high-voltage electron microscope. Dislocation loops nucleated on both stacking-fault planes and in the matrix by irradiation with electron accelerated through voltages higher than 700kV at room temperature. Two types of loops with the Burgers vectors b = ½c and b = a existed in the matrix, where a = 1/3<2110> and c = [00•1]. On the other hand, loops with b = ½c + a/3 and those with b = ½c were formed on the prismatic fault planes and basal fault planes, respectively. Diffraction-contrast experiments showed these loops to be of interstitial type. A re-irradiation experiment after the annealing indicates a possibility that there exist vacancies in the matrix at 700C.

Studies of Dislocation Loops Produced by Irradiation of ZnO in a High-Voltage Electron Microscope. Yoshiie, T., Iwanaga, H., Shibata, N., Suzuki, K., Takeuchi, S.: Philosophical Magazine A, 1980, 41[6], 935-42