scanning electron microscope sumeet

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Sumeet S. Sumeet S. ChavanChavan

MSc.-II, Sem-IVMSc.-II, Sem-IV

Paper-IIIPaper-III

Contents

Introduction.Principle.Sample preparation.Instrumentation and Working.Applications.

Principles of SEM

When electron beam strikes sample, large number of signals are generated

- Observe surface topography and morphology at high resolution.- Observe rough or raised-feature surface with great depth-of-field Measure thin film and coating thickness with calibration standard reference.- Measure the size of surface features, particle sizes and determine particle shapes.- Find number and density of surface defects.- Examine precipitates at grain boundaries.

Sputter Deposited Platinum

A thick layer of sputter deposited Pt on a curved surface shows layering with sharp crystallographic separations, producing an overall “shingled” appearance at relatively low magnification.  This is a case in which the great depth of focal field of the SEM compared to optical microscopy is very useful.

- H.H. Willard, L.L. Merrit, J.A. Dean and F.A. Settle, Instrumental Methods of Analysis.