Paramagnetic resonance in yttrium gallium garnet: Co²⁺and Mn²⁺

Measurements have been made of the paramagnetic resonance spectra of Mn 2+ and Co 2+ ions in Y 3 Ga 5 O 12 . Both ions were in octahedral sites. For Co 2+ the g values were close to the weak field limit so that further analysis was made. The trigonal field parameter was estimated to be 810 cm -1 and the nuclear hyperfine parameters P = 0.0205 cm -1 and κ = 0 26. For Mn 2+ the D parameter is large and negative (-0 0879 cm -1 ). This is apparently due to the fact that A 2 0 is negative and that for Mn 2+ there is a large dependence of D on ( A 2 0 ) 2 .