Local Vibrational Modes of Boron in Garnets

Abstract
Local vibrational modes of boron impurities have been detected in single crystals of Y3Fe5O12, Gd3Fe5O12, Y3Ga5O12, and Gd3Ga5O12, which were grown from a melt containing B2O3 flux. The B3+ ion is incorporated on a heavily distorted defect site, in threefold oxygen coordination. From the energetic position of the spectra, five different boron‐oxygen complexes may be distinguished. As the analysis shows, the (BO3)3− groups must be associated with a further lattice defect of complex and multiform structure.