Strain mapping in TEM using precession electron diffraction
AssigneeDrexel University
InventorsMitra Lenore Taheri, Asher Calvin Leff
Life of this patent
Estimating the term…
Abstract
A sample material is scanned with a transmission electron microscope (TEM) over multiple steps having a predetermined size at a predetermined angle. Each scan at a predetermined step and angle is compared to a template, wherein the template is generated from parameters of the material and the scanning. The data is then analyzed using local mis-orientation mapping and/or Nye's tensor analysis to provide information about local strain states.
Claims20
A method for strain mapping a material comprising the steps of:
- scanning a sample of a material with a transmission electron microscope (TEM), wherein the scanning of the material occurs over multiple steps having a step size and at a beam precession angle;
- comparing each scan at each step and beam precession angle to a template to produce data, wherein the template is generated from parameters of the material and information from the scanning step;
- analyzing the data using local mis-orientation mapping analysis or Nye tensor analysis;
- and
- producing a local strain map of the sample.
The method of 1, wherein the step of analyzing is performed using Nye tensor analysis, and a least squares contortion value is calculated for each of the multiple steps.
A method for strain mapping a material comprising the steps of:
- scanning a sample of a material with a transmission electron microscope, wherein the scanning of the material occurs over multiple steps having a step size and an angle;
- comparing each scan at each step and angle to a template, wherein the template is generated from parameters of the material and information from the scanning,
- analyzing the data using Nye tensor analysis, wherein a best fit of a Nye tensor for each predetermined step is calculated;
- and
- producing a local strain map of the sample.
Dependencies are inferred from the claim text.