Thermal and mechanical properties of Cd metal nanopowder by Hall Williamson method

Abstract

The present work is a purely experimental study aimed at systematic determination of the Debye-Waller factors, Debye temperatures, particle size, lattice strain and amplitudes of vibration of cadmium (Cd) atoms in metallic systems from X-ray intensity measurements. Cadmium (Cd) powder was prepared by ball milling (BM) method; it was characterized by X-ray diffraction and Hall Williumson method. The residual powder was processed in a ball mill for 6, 12, 18, 24, and 28 h to create strain due repeating grinding/milling the given powder and also reduces particle size from 190 nm for zero hours and 17 nm for 28 hoursof ball milling time. X-ray diffractograms were taken of zero hours as initial sample and also taken after each spell of 6 h milling time. As Milling time increases systematically (from zero to 28 h); the Debye-Waller factor (from 1.80 Å2 to 2.76 Å2) and the lattice strain (from 1.19 × 103 to 4.27 × 103) also increases systematically. From the correlation between the strain and effective Debye-Waller factor, the Debye-Waller factors for zero strain have been estimated for Cd. The variation of energy of vacancy formation as a function of lattice strain has been studied.