I am using Digital micrograph for calculation of lattice spacing from HR-TEM image but i don't know how to do it. I think first we have to calibrate the image.
Hi
Its very simple, I am also doing this with the same program!
1.- copy and paste the micrograph in the program
2.- Select with the square of the ROI tools the area of the micrograph of interest
3.- Click ALT and left buttom of mouse to "reconstruct" the selection you make
4.- Click Process of the menu bar, and then select FTT or CTLR+ F
5.- With the tools of Display Control, improvement the image (Brightness, contrast and Gamma)
6.-Then in the standars tools select the one that its a sigmoidal graph and conect the "points" you obtained
7.- You are going to obtain a graph like a histogram,
8.- So, put you cursor and select the area between the two bars similar in height, (you can see also the selection in the micrograph to be more confidence)
9.- The distance you obtained is #/nm, and its the total of the 2 points, so you have to divide the result into 2, and the obtain its inverse and multiply for 10, you are going to obtain this result in angstroms.
10.- Compare you results with the fcc tables
I hope this could help you!! =D
Once you've correctly set the scale of the image, you'll need to know the camera length and you'll have to have correctly indexed the diffraction pattern. The distance, r[hkl], between the 000 spot and the hkl spot is related to the (hkl) plane spacing, d[hkl], by
r[hkl] = lambda * L / d[hkl]
where lambda is the electron wavelength and L is the camera length. Use DM to measure r[hkl] and then calculate d[hkl] using the above equation.
A simple overview can be found on our website at http://www.doitpoms.ac.uk/tlplib/diffraction-patterns/index.php - see particularly the page 'Mathematics relating the real space to the electron diffraction pattern'.
Volker,
Thanks for correcting me. I've only heard of people using DM to analyse images (as opposed to diffraction patterns) and the software I use for making measurements on diffraction patterns does not have that feature. I apologise for confusing the discussion!
Still, the diffraction pattern must be properly indexed if the lattice parameters are to be obtained... and it's never a bad thing to understand the underlying science behind any automatic calculation!
Thanks to all. These suggestions helped me a lot and able me to solve my problem.
Hi
Its very simple, I am also doing this with the same program!
1.- copy and paste the micrograph in the program
2.- Select with the square of the ROI tools the area of the micrograph of interest
3.- Click ALT and left buttom of mouse to "reconstruct" the selection you make
4.- Click Process of the menu bar, and then select FTT or CTLR+ F
5.- With the tools of Display Control, improvement the image (Brightness, contrast and Gamma)
6.-Then in the standars tools select the one that its a sigmoidal graph and conect the "points" you obtained
7.- You are going to obtain a graph like a histogram,
8.- So, put you cursor and select the area between the two bars similar in height, (you can see also the selection in the micrograph to be more confidence)
9.- The distance you obtained is #/nm, and its the total of the 2 points, so you have to divide the result into 2, and the obtain its inverse and multiply for 10, you are going to obtain this result in angstroms.
10.- Compare you results with the fcc tables
I hope this could help you!! =D
@Dr. Volker Klemm,
I have the same problem, In Object-> Image display-> Calibration-> Scale
It is written that it is in a scale of 1.
What does inner external standard means?
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