Dear Rietvelders,
To avoid the gigantic peaks of Si substrate (which are too dominant over
peaks of phases in investigation on a thin film of 3 micron), we have
tried to take a scan theta-two theta with a shift of 3 degree for theta
(i.e. instead of theta-2theta corresponding to 5-10 degree
Besides Joerg's suggestion of mis-cut substrates (which may be too
expensive for use for thin film growth experiments) you could use Si
wafers cut to (100). The first allowed peak in that direction is (400),
which is at about 70 degrees 2theta for Cu K-alpha. That will still
reflect any
Dear Huy,
as it was pointed out in previous letter by Joerg Bergmann, line broadening
is caused by violation of theta-2theta relationship.
More info can be found in the following articles:
1. R. Berthold. Z. Angew. Phys. 7 (1955) 443.
2. H. Toraya, J. Yoshino. J. Appl. Cryst. 27 (1994) 961.
Such an offset of the theta (omega) axis violates the para-focusing
condition of the Bragg-Brentano geometry. You will get diffracted
intensity from positions far below and above the gonimeter axis, i.e.
far outside the focusing circle. The only option to reduce this effect
is a reduction of
