Threshold displacement energy in yttria‐stabilized zirconia

Abstract

AbstractWe have studied the color center production in yttria‐stabilized zirconia single crystals (i.e. ZrO2: Y with 9.5 mol% Y2O3) with the (100) orientation, by electron irradiations at energies ranging between 1.0 and 2.5 MeV. Electron paramagnetic resonance (EPR) measurements show that three paramagnetic centers are stable at room‐temperature: i) an F+‐type center (singly ionized oxygen vacancy), ii) the so‐called T‐center (Zr3+ in a trigonal oxygen environment), and iii) a hole center. The growth curves of F+‐type centers at variable electron energy cannot be rescaled versus the absorbed dose. These data confirm that F+‐type center production is primarily governed by elastic collision processes with a threshold electron energy about 1.0 MeV. This can be correlated to a threshold displacement energy either about 120 eV for the O‐atoms in the collision cascades, or about 80 eV for the Zr‐ (or Y‐) atoms. In contrast, the growth curves of T‐centers at variable electron energy are rescaled versus the absorbed dose. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)