// Script to compute the High Frequency Dielectric Constant // based on equation 9 in Gass et al., Phys. Rev. B73, (2006) 035312. // This image takes as its input the front-most image which must be // Epsilon2 data from Kramers Kronig analysis (KKA). This data can be // in the form of a 1D intensity profile, a 2D spectrum image or a 3D spectrum image. // EELS data must have plural scattering and low loss removed prior to // carrying out KKA. Have the Epsilon2 data file shown front-most and then // run this script. // D. R. G. Mitchell, adminnospam@dmscripting.com (remove the nospam to make this address work) // version:20200814, v1.0, August 2020 // Acknowledgements: The integration code is based on some Gatan code, by an anonymous author. // Source the front-most image number nodocs=countdocumentwindowsoftype(5) if(nodocs<1) { showalert("Ensure Epsilon2 data from KKA is displayed.\n\nData can be in the form of : an intensity profile, a 2D SI or a 3D SI.",2) exit(0) } image front:=getfrontimage() image efDC // Get some data from it number xsize, ysize, zsize string imgname=getname(front) try { get3dsize(front, xsize, ysize, zsize) } catch { getsize(front, xsize, ysize) break } // Decide what kind of image it is : spectrum, 2D SI, or 3D SI number sizeflag=0 if(zsize>1) sizeflag=3 // 3D SI if(zsize==1 && ysize>1) sizeflag=2 // 2D SI if(xsize>1 && ysize<=1) sizeflag=1 // Spectrum if(sizeflag==0) { showalert("The front-most image must be Espilon2 data from Kramers-Kronig Analysis. The image can be a spectrum, a 2D SI or a 3D SI.",2) exit(0) } // Main processing section if(sizeflag==3) // it is a 3D spectrum image { // Create images to store the individual spectra and output image clone=imageclone(front) image output=realimage("", 4, xsize, ysize) // Get calibration info number origin, scale, dimension=2 // z axis is the energy axis string units origin=front.imagegetdimensionorigin(dimension) scale=front.imagegetdimensionscale(dimension) // Create a 'spectrum' in which each channel contains the energy value of that channel image energyloss=realimage("", 4, zsize, 1) energyloss=icol*scale+origin // Create a clone of the spectrum image and divide the SI by the energy of each channel image energy:=imageclone(front) energy/=energyloss[iplane, icol, irow] //Remove information below 0 eV - ch0eV is the channel at which the energy is 0eV number ch0eV = ceil(-origin/scale) energy[0,0,0,xsize,ysize,ch0eV+1]=0 // Do the integration image integral:=imageclone(energy) integral = integral[icol,irow,iplane] + integral[icol,irow,iplane-1] // Calculate the effective dielectric constant efDC=imageclone(front)*0 efDC=1+2/pi()*integral*scale } if(sizeflag==2) // 2D SI { // Create images to store the individual spectra and output image clone=imageclone(front) image output=realimage("", 4, xsize, ysize) // Get calibration info number origin, scale, dimension=0 // x axis is the energy axis string units origin=front.imagegetdimensionorigin(dimension) scale=front.imagegetdimensionscale(dimension) // Create a 2D 'spectrum image' in which each channel contains the energy value of that channel image energyloss=realimage("", 4, xsize, ysize) energyloss=icol*scale+origin // Create a clone of the spectrum image and divide the SI by the energy of each channel image energy:=imageclone(front) energy=energy/energyloss //Remove information up to 0 eV number ch0eV = ceil(-origin/scale) energy[0,0,ysize, ch0eV]=0 // Do the integration image integral:= imageclone(energy) integral= integral[icol, irow]+integral[icol-1, irow] efDC=imageclone(integral)*0 efDC=1+2/pi()*integral*scale } if(sizeflag==1) // Spectrum { // Define some variables and source the calibration of the image number i, Eeff number scale, origin, dimension=0 // x axis is the energy axis scale=front.imagegetdimensionscale(dimension) origin=front.imagegetdimensionorigin(dimension) // Create a 'spectrum' to store the energy of each channel image energyLoss = RealImage("Energy loss",4,xsize,1) energyLoss = icol*scale+origin // Divide the 1D spectrum by the energy of each channel image eps2spectrum:=imageclone(front) eps2spectrum=eps2spectrum/energyloss //Remove information up to 0 eV number ch0eV = ceil(-origin/scale) eps2spectrum=tert(icol<(ch0eV+1), 0, eps2spectrum) // Do the integration image integral:= imageclone(eps2spectrum) integral = integral[icol, irow]+integral[icol-1, irow] efDC=imageclone(integral)*0 efDC=1+2/pi()*integral*scale } // Copy across calibrations and tags imagecopycalibrationfrom(efDC, front) taggroup efDCtags=efDC.imagegettaggroup() taggroup fronttags=front.imagegettaggroup() taggroupcopytagsfrom(efDCtags, fronttags) // Get the size and position of the original spectrum image showimage(front) documentwindow frontwin=getdocumentwindow(0) number top, left, bottom, right frontwin.windowgetframebounds(top, left, bottom, right) number displayheight=bottom-top number displaywidth=right-left // Display the output at the same size and directly to the right of the original. // If that would put it outside the screen area, display below the original. // If that too would put it off the screen area - display top left. number screenwidth, screenheight getscreensize(screenwidth, screenheight) showimage(efDC) setname(efDC, "Effective Dielectric Constant") documentwindow outputwin=getdocumentwindow(0) number posflag=0 if(right>=(screenwidth*0.9)) posflag=1 // 90% of the screen width is the limit chosen if(bottom>=(screenheight*0.9)) posflag=posflag+2 // ditto bottom of the screen if(posflag==1)outputwin.windowsetframebounds(bottom, left, bottom+displayheight, right) if(posflag==0 || posflag==2)outputwin.windowsetframebounds(top, right, bottom, right+displaywidth) if(posflag==3) windowsetframebounds(outputwin, 0,0, displayheight, displaywidth)