Ion distribution and saturation magnetization of aluminum substituted lithium ferrites

Ion distribution is determined in a series of aluminum substituted lithium ferrites by carefully analyzing the powder X-ray diffraction patterns. A new finding is that Al/sup +3/'s substitute the Fe/sup +3/'s in tetrahedral sites as well as in octahedral sites of the spinel structure. The proper formula, then, is (Fe/sub 1-a//sup +3/Al/sub a//sup +3/)[Li/sub 0.5//sup +/Fe/sub 1.5-(x-a)/Al/sub x-a//sup +3/]O/sub 4/, where a is approximately 0.23x/sup 2/+0.22x. The saturation magnetizations are calculated and compared with the measured values.