Reflectivity of YIG and YGG: Observation of charge transfer and crystal field transitions

The reflectivity spectra of yttrium iron garnet (YIG, Y3Fe 5O12) and yttrium gallium garnet (YGG, Y 3Ga5O12) have been measured in the energy range 2-7.5 eV. Structure is observed in YIG which can be attributed to charge-transfer-enhanced crystal field transitions and in YGG to critical point transitions. © 1967 The American Institute of Physics.