Growth of mercuric iodide crystals

Full text
Author(s):	J. C. Ugucioni ; M. Ferreira ; F. Fajardo ; M. Mulato Total Authors: 4
Document type:	Journal article
Source:	Brazilian Journal of Physics; v. 36, n. 2a, p. 274-277, Jun. 2006.
Abstract
Mercuric Iodide (HgI2) is a semiconductor candidate for the construction of X- and gamma-ray detectors for digital medical imaging due to its high atomic number (Z Hg = 80, Z I = 53). Also, HgI2 has a wide optical band-gap (2.13 eV) and high photon absorption coefficient for high-energy radiation. Different structures can lead to varying electrical and optical properties of the final material. In this work, HgI2 crystals were produced by the solvent evaporation technique. The solvents used were ethanol (solubility around 20 mg/ml at 25ºC), ether (solubility around 3.5 mg/ml at 25ºC) and acetone (solubility around 24mg/ml at 25ºC). The evaporation conditions were varied in order to produce different final crystals. The Bérnard cells are responsible for crystallites formation due to the Bérnard-Maragoni convection in the liquid. Millimeter-sized crystals can be obtained as seen by Scanning Electron Microscopy. (AU)