Polare Eigenschaften von Zinkoxid-Kristallen.

A polar c-axis must be attributed to the wurtzite structure of zinc oxide. The sign of the c-axis can be determined by cleaving perpendicular to this axis and subsequent etching of the exposed {0001} surfaces. The present paper reports how this can be achieved without cleavage, merely by etching the prism faces {10¯10} which are the principal surfaces of hexagonal needles and of thin platelets. The etch patterns unambiguously point into the direction of the positive c-axis. This method is applied not only to the prism faces but also to cleaved surfaces of the same orientation. A close relation between etch patterns and lattice defects is apparent. [ABSTRACT FROM AUTHOR]