Artifacts in Transmission Electron Microscopy - Sample Preparation Topic for Transmission Electron Microscopy - page 129

Techniques involved: mechanical polishing, dimpling, tripod polishing, and
ultramicrotomy.
Crystal-network change : Change in the geometry of the crystalline structure
and/or the crystalline motif. Any mechanical action can cause additional
changes to the crystal network, such as dislocations, glide planes, twinning,
and strain hardening.
Techniques involved: sawing, ultrasonic cutting, mechanical polishing, dim-
pling, tripod polishing, and ultramicrotomy.
Composition change : Change in the elemental composition of the sample due
to a loss or dissolution of chemical elements during preparation.
Techniques involved: ultramicrotomy.
Residues : Deposits of matter extrinsic to the sample that may be polishing or
sectioning residues resulting from preparation. They are superimposed on the
thin slice and impede its observation. Residues are produced by mechanical
actions during preliminary preparation or during final thinning.
Techniques involved: mechanical polishing, grinding, tripod polishing, ultra-
microtomy, and cryo-ultramicrotomy.
2.1.1 Secondary Thermal Damage Induced During Mechanical Preparation
Fusion : Change of the solid-liquid physical state of a solid sample. It can be
caused by an increase in temperature during mechanical preparation.
Techniques involved: mechanical polishing and tripod polishing.
Phase transformation : Total or partial transformation of the crystallographic
and/or chemical structure, which can be caused by thermal effects during
mechanical techniques.
Techniques involved: sawing, mechanical polishing, dimpling, and tripod
polishing.
Loss of chemical elements : Selective loss of a chemical element, which may
be caused by secondary thermal effects during mechanical preparation.
Techniques involved: sawing, mechanical polishing, dimpling, and tripod
polishing.
Amorphization : Partial or total degradation of the chemical bonds of a crys-
talline sample, resulting in its destruction. This type of defect is caused by
thermal effects during the mechanical action of preparation.
Techniques involved: mechanical polishing and tripod polishing.