gains tutorial
DESCRIPTION
Gains Tutorial. Andy Therrien. Uncorrected Image Ni/Cu alloy CO dose and 120 K anneal Atomic Resolution 80 K Image. Uncorrected Image 5 Deg off horizontal Measure across 39 Cu atoms X Component: Cos(5) = X/H Actual: H = 9.6509 nm X = 9.614 nm Theoretical: H = 0.256 x 39 - PowerPoint PPT PresentationTRANSCRIPT
Uncorrected Image
5 Deg off horizontal
Measure across 39 Cu atoms
X Component:Cos(5) = X/H
Actual: H = 9.6509 nmX = 9.614 nm
Theoretical:H = 0.256 x 39 = 9.984 nmX = 9.946
X Correction:9.946/9.614 = 1.035
Adjacent = X
Hypotenuse
Uncorrected Image
0.5 Deg off vertical(more evidence that there is an angle error in raw image)
Measure across 31 root 3 Cu spacings
Y Correction:Cos(0.5) = A/H
Actual: A = 9.6395 nmH = 9.639 nm
Theoretical:A = (√3)0.256 x 31 = 13.746 nmH = 13.745
Y Correction:13.745/9.639 = 1.426
Adjacent = Y
Hypotenuse
Apply the Gains
Measure over 10 atoms in each close packed direction(so each should be 2.56 nm)
2.5896 nm (1.2% error)
2.4173 nm (5.6% error)
2.7272 nm (6.5% error)
The one we calibrated for is really good but the other two are off
Unit Cell Detection
Software tells you what to do
In dialog box select oblique
Set your angle to 60 (or 120 depending of unit cell)
Set La and Lb to whatever you made your unit cell(so this is 7 by 8 atoms so its 1.792 by 2.048)
Hit apply and make sure the correction factors at the bottom are reasonable