Crystal Structure of (NH4)2SO4-K2SO4 Mixed Crystal

Crystal structure of mixed crystals [(NH 4 ) 1- x K x ] 2 SO 4 , x =0.31 4 and 0.70 0 , has been studied by x-ray diffraction. The mixed crystals are found to be isomorphous to ammonium sulfate and potassiunn sulfate crystals. A tendency is found that potassium ions accomodate preferentially on site (2) rather than on site (1), where site (1) and site (2) are not crystallographically equivalent positions. A quantitative result is given for the accomodation of potassium ions on the two sites.