Add more standard Q values into the program

[joshualande]

Original author: joshuala...@gmail.com (February 23, 2008 18:27:36)

This would make it easier to use.

Original issue: http://code.google.com/p/areadiffractionmachine/issues/detail?id=24

[joshualande]

From zgainsfo...@gmail.com on September 19, 2010 04:15:40
Here are two Q files I use fairly regularly...

Al2O3 is obvious, Si3N4 is from silicon nitride membranes that I sometimes use for mounting XRF samples. The Si3N4 bands are not as accurate as Al2O3 or other standards because of the strain fields in the thin membranes. Nevertheless, I still find it useful for samples that don't require high accuracy because my sample then has a built in diffraction standard.