residue was dried in a laboratory drying oven at 60 u00b0 c in air for 24 hrs to form 15 67 g of a dry powder compact the oven dried powder compact was then hand ground in a mortar and pestle to from a uniform dry powder each of two mixture components eu 0 02 ca 0 98 f 2 02 u2212 2y o y shown as mc1 in table 2 and eu 0 02 sr 0 98 f 2 02 u2212 2y o y shown as mc2 in table 2 were prepared by the method of examples 1 3 except that in each case only one alkaline earth chloride was employed in the preparation of each of the mixture components as shown in table 2 in fig2 are the individual x ray diffraction patters of eu 0 02 sr 0 98 f 2 02 u2212 2y o y and eu 0 02 ca 0 98 f 2 02 u2212 2y o y represented as broken lines one 15 g aliquot of each mixture component was separately hydrothermally heated as described above in examples 4 6 following heating and drying the dried powders of the hydrothermally heated mixture components were combined in the molar ratios shown in table 3 and.