Abstract

The stoichiometry of HgI2 is reviewed as a function of the various stages of preparation including synthesis, purification, crystal growth and ending with device fabrication. Original data are presented on surface roughness of free surfaces of HgI2 determined by variable angle spectroscopic ellipsometry (VASE) and atomic force microscopy (AFM) and their relation to stoichiometry. The spread of the “c” lattice constant variation in bad HgI2 nuclear detectors was determined by triaxial X-ray diffraction (TAXRD), and the results are discussed in relation with deviation from stoichiometry. It is suggested that crystals purified by open tube sublimation are stoichiometric. However, high temperature purification treatments, such as melting and even growth, may induce a certain dissociation of HgI2 into Hg2I2 and free iodine. The latter diffuses, through a complex process, out of the crystal leaving a very rough outer surface and inhomogeneous stoichiometry in the bulk, which may be detrimental to device performance as a nuclear radiation detector.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.