Crystals of highly purified thallium bromide were used to fabricate radiation detectors. These detectors were rested with isotopic photon sources and successfully detected gamma and X-rays in the 0.01- to 1 MeV energy range. The detectors were tested at and below room temperature, and their performance approaches that of other semiconductor detector materials which have been under development. The performance of TlBr detectors is due to the similarity in the transport characteristics of electrons and holes in TlBr and the relatively large number of charge carriers produced per unit of energy of detected particle. The performance of these detectors is currently limited by shot noise induced by the leakage current in the TlBr. >

Thallium bromide radiation detectors

A survey of the phenomenon of polytypism in crystals

Semiconductor radiation detectors have been fabricated from melt grown crystals of lead iodide (PbI2) and the performance of these detectors as room temperature X-ray spectrometers has been measured. These detectors exhibit good energy resolution (915 eV FWHM for the 5.9 keV peak of 55Fe at 20°C). Preliminary results indicate they are more stable than HgI2 detectors and capable of operating at temperatures over 100°C.

Properties of lead iodide semiconductor radiation detectors

Melt-grown lead iodide single crystals with an improved transport of positive charge carriers (holes) have been developed. It is shown that an energy resolution of about 3% can be obtained for gamma-radiation at 60 keV (241Am isotope source). Improvement of the spectrometric performance of lead iodide detectors at lower gamma-ray energies has been achieved as well due to better purification of the starting material and optimization of the etching procedure. Correlation between the detector performance and the structure of lead iodide crystals has been studied using X-ray diffraction analysis.

Improved performance lead iodide nuclear radiation detectors

The preparation of radiation detectors from semiconducting lead iodide is discussed, and the performance of these devices as X-ray and gamma-ray spectrometers is evaluated. Detectors prepared from melt-grown crystals exhibit good energy resolution for low-energy ( >

Lead iodide nuclear spectrometers

Purification, growth and polytypism of single crystals of lead iodide

Purification and growth of single crystals of cadmium iodide by zone refining and study of their polytypism by x-ray diffraction

Lead iodide is a wide-band gap and highly resistive semiconductor considered to be a promising room temperature nuclear detector. The phenomenon of polytypism is posing interesting problems of phase transformations among its polytypic modifications and formation of polytypic admixture during growth due to native impurities. Transformations have also been observed even when the material is stored for few months that causes deterioration in functioning of the PbI2 devices. Lead iodide has been purified and single crystals were grown using zone-refining system. The observed phase transformations during growth and storage have been explained in the light of distortion of [PbI6]4- octahedron due to impurities present in the material and the known crystal structures of PbI2. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Impurity induced structural phase transformations in melt grown single crystals of lead iodide

Purification and growth of ferroelectric sodium nitrite single crystals using zone-refining technique

http://journals.iucr.org/c/issues/1983/06/00/a22460/a22460.pdf

S. K. Chaudhary

Papers

Purification, growth and polytypism of single crystals of lead iodide

Purification and growth of single crystals of cadmium iodide by zone refining and study of their polytypism by x-ray diffraction

Impurity induced structural phase transformations in melt grown single crystals of lead iodide

Purification and growth of ferroelectric sodium nitrite single crystals using zone-refining technique

Structures of five large‐period polytypes of cadmium iodide