OH BANDS IN (DY1-XGDX)(3)GA5O12, DY-3(GA1-YALY)(5)O-12 AND RELATED OXIDES GROWN BY THE CZOCHRALSKI METHOD

The OH bands at similar to 3600 cm(-1) in (Dy1-xGdx)(3)Ga5O12 and Dy-3 (Ga1-yAly)(5)O-12 garnet single crystals have been measured at room te mperature by Fourier-transform infrared spectroscopy for the first tim e. The noticeable OH bands were observed for the above garnets, wherea s no corresponding bands were detected for Gd3Ga5O12 and Y3Ga5O12 garn ets containing no Dy as a component. Based on the thermal-desorption s pectra of Dy3Ga5O12 and Gd3Ga5O12 garnets, it is concluded that the OH bands originate from the constituent elements susceptible to atmosphe ric humidity during the crystal growth; the strong affinity of Dy with hydrogen can account for the appearance of the OH bands. The results are also discussed with regard to the unstable spiral-shape growth of single crystals.