J. Birch et al., MEASUREMENT OF THE LATTICE-PARAMETERS IN THE INDIVIDUAL LAYERS OF SINGLE-CRYSTAL SUPERLATTICES, Journal of applied physics, 78(11), 1995, pp. 6562-6568
A method for determination of the lattice parameters, parallel to the
sample surface as well as normal to the sample surface, in the individ
ual layers of single-crystalline superlattices is derived. The method
is based on simulations of low angle reflectivity measurements in comb
ination with x-ray diffraction reciprocal space mapping. The number of
unknown simulation parameters is reduced from three to one, namely th
e layer thickness of one of the layers which constitutes the bilayer p
eriod, if compared to techniques based only on simulations of the high
angle diffraction pattern. The technique is demonstrated by character
izing a single-crystalline Mo/V(001) superlattice grown by dual-target
magnetron sputtering onto MgO(001) substrates. The lattice parameters
of the tetragonally distorted layers were a(Mo)=0.309 nm, c(Mo)=0.319
nm, a(V)=0.305 nm, and c(V)=0.298 nm which correspond to a misfit dis
location density of similar to 0.056 dislocations per nm at each inter
face and a relaxation of similar to 1/3 of the coherency strain. The l
attice parameters obtained by the method were confirmed by comparing a
kinematical calculation of the high angle Mo/V(002) theta-2 theta dif
fraction pattern (using the obtained values as input parameters) with
the experimentally determined pattern. (C) 1995 American Institute of
Physics.