New Paramagnetic Center in Cu-Doped Y-Stabilized ZrO₂

Abstract

The results of electron paramagnetic resonance (EPR) of Cu-doped Y-stabilized ZrO 2 powders calcined at 800 °C-1000 °C are presented. It was found that the calcination of the samples at high temperatures leads to dramatic modification of EPR spectrum and appearance of new Cu-related signal. Computer simulations of both X-and Q-band spectra allowed to determine the following parameters of the copper centers: S = 1/2, I = 3/2, g x = 2.021, g y = 2.026, g z = 2.168, A xx ∼ 40 × 10 −4 cm −4 , A yy ∼ 35 × 10 −4 cm −4 , A zz ∼ 186 × 10 −4 cm −4 , A xz ∼ 10 × 10 −4 cm −4 , A yz ∼ 5 × 10 −4 cm −4 for the 63 Cu isotope. The analysis of the experimental data allows proposing center model as Cu Zr 2+ in the monoclinic ZrO 2 lattice. The comparison with photoluminescent data allows assumption that EPR center investigated participate in the light emission process.