Variable Temperature Laser Light Scattering Microscopy (VTLLSM) Studies on 10-100 μm Size High Purity Gold and Commercial Grade Zinc Grains

P Sita Rama Rao,P B V Prasad,P B Shashikanth

doi:10.4236/msa.2010.16048

Abstract

The VTLLS microscopy studies were made on high purity gold and commercial grade zinc grains in a temperature range of 30-230?C. Differential area ω and surface activity Sa were estimated from photomicrographs. The ω vs dT/dt (rate of heating) curve was seen to differ from those of silver and titanium. The nature of curve between normalized ω and dT/dt was seen to be non-exponential. The characteristic relation between sectorized differential area ωsec and mean temperature was examined. The present study further establishes the simplicity and versatility of the VTLLS technique, in studying the defect-sub-structure of metal particles such as Au and Zn in presence of an imposed temperature gradient in a reasonable way. As such an attempt was made to connect the ω and defect-sub-structure related parameters.

Highlights

Studies on defects in materials and metals have been a fascinating subject and many techniques were developed to support such investigations
The VTLLS microscopy studies were made on high purity gold and commercial grade zinc grains in a temperature range of 30-230 ̊C
The technique was similar to the variable oblique incidence reflection microscopy (OIRM) reported by the present authors [7]

Summary

Introduction

Studies on defects in materials and metals have been a fascinating subject and many techniques were developed to support such investigations. The present authors [6] made variable temperature laser light scattering microscopy (VTLLSM) studies on relatively larger grains of aluminum, copper and silver in a small temperature interval and established the effectiveness of the technique. The new technique consists of the Fourier space interference images (resulted from light scattered by particles), which is the intermediate step in the formation of a holographic image. Such an image is composed of black and white contrast regions, which were attributed to surface micro-facets of the particles. Investigations were made on 10-100 μm size gold and zinc grains, by employing variable temperature laser light scattering microscopy (VTLLSM).

Experimental

Results

Discussion

Conclusions