Ma. Strzhemechny et al., THE STRUCTURE AND THE ORIENTATIONAL ORDER-PARAMETER OF AR-CO2 SOLID-SOLUTIONS, Low temperature physics (Woodbury, N.Y.), 24(9), 1998, pp. 669-678
Electron diffraction studies of the structural characteristics of Ar-C
O2 solid solutions are carried out over the entire range of their mutu
al concentrations. The regions of low concentrations of both component
s are analyzed in detail and the relative excess volumes Delta upsilon
/upsilon are determined for the CO2 impurity in solid Ar (Delta upsilo
n/upsilon similar or equal to 0.8), and for the Ar impurity in solid C
O2 (Delta upsilon/upsilon similar or equal to 0.28). The experimental
results and relationships are compared with the results obtained from
the semi-quantitative theory on the basis of known atom-atom potential
s. An expression relating the intensity of superstructural reflections
I-(super) (including the reflection 210) with the long-range orientat
ional order parameter eta is obtained. It is found that I(210)proporti
onal to eta(2) to a high degree of precision. The experimental depende
nce of the orientational order parameter eta on the argon concentratio
n in solutions rich in CO2 is obtained. (C) 1998 American Institute of
Physics. [S1063-777X(98)01209-2].