Manganese Substitution in Garnets for Remanent Phase Shifters (Correspondence)

Results of experiments to determine the effect of small manganese substitution on the properties of mixed yttrium-gadolinium garnets are reported. The composition Y/sub 2.1/Gd/sub 0.9/Fe/sub 5-z/ Mn/sub z/0/sub 12/ (0<z<0.15) has been investigated, and the variation of remanent properties, resonance linewidth, and dielectric loss tangent are given. It is shown that the use of manganese can lead to a significant reduction in the variation of remanent phase shift with external stress, and the composition with z = 0.15 is shown to be comparable with magnesium-manganese-aluminium spinel in this respect.