Crystallographic polarity and chemical etching of CdxHg1−xTe

Abstract

The absolute crystallographic polarity of Cd_xHg_1−xTe crystals (x?0.2) has been determined using the anomalous scattering of x rays and correlated with the chemical etching characteristics. It is shown that Cr Kα radiation adequately distinguishes 333 and 3̄3̄3̄ reflections, and that the reflected intensities agree closely with theoretical calculations. Using a range of chemical etchants it is reported that dislocation etch pits are revealed on the (111) or A face, i.e., the face terminating with triply bonded Cd (Hg) atoms or singly bonded Te atoms, and not on the (1̄1̄1̄) or B face.