Paramagnetic platinum centres in paratellurite

Abstract

In TeO2 single crystals grown in Pt crucibles a new orthorhombic paramagnetic Pt-related centre was observed. From the analysis of the ESR spectra it was concluded that it is a Pt3+ impurity ion on an undistorted Te4+ site with gxx=2.5976, gyy=2.0996, gzz=1.9388 and that the 195Pt hyperfine principal values (in 10-4 cm-1) are Axx=191,Ayy=69 and Azz=46. On the basis of the properties of this centre it could be proposed that the model for another Pt-related centre observed earlier in electron irradiated TeO2 is a V0 centre with a Pt4+ in a next-nearest position.