K. A. Hussain

Melting temperatures of some alkali halide mixed crystal systems

The melting points in the KCl-KBr, RbCl-RbBr and KBr-RbBr mixed crystal systems have been measured using the microscopic method. In all the three systems, melting points vary nonlinearly with composition, with negative deviations from linearity and maximum deviation at about the equimolar concentration. The observed composition dependence of the melting points is explained qualitatively in terms of the enhanced concentration of point defects and dislocations in mixed crystals.

Raman Spectral Investigations on Enhancement of SHG Efficiency by Thiourea Doping in Bis Glycine Cadmium Chloride Single Crystals

This paper presents the enhancement of second‐harmonic generation (SHG) efficiency by doping thiourea in centrosymmetric semiorganic bis glycine cadmium chloride (BGCC) single crystals. Raman spectroscopy was used to identify the presence of functional groups of BGCC and also study the incorporation of thiourea in to doped crystal matrix. The strongest vibrational modes contributing to the SHG enhancement are identified as 1417 cm−1, 1447 cm−1, 1457 cm−1, 1491 cm−1 and 2949 cm−1.

Design and fabrication of a high temperature X-ray powder diffraction camera

A high temperature X-ray powder diffraction camera has been designed and fabricated with indigenous material. The camera design is similar to the Unicam model but overcomes some inconvenient features of the latter. The camera incorporates a miniheater which is inexpensive and easily replaceable. The camera enables determination of lattice parameters with an accuracy of ±0.0002 Å up to 800°C.