New Paramagnetic Center in Cu-Doped Y-Stabilized ZrO2

The results of electron paramagnetic resonance (EPR) of Cu-doped Y-stabilized ZrO2 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, gx = 2.021, gy = 2.026, gz = 2.168, Axx ∼ 40 × 10−4 cm−4, Ayy ∼ 35 × 10−4 cm−4, Azz ∼ 186 × 10−4 cm−4, Axz ∼ 10 × 10−4 cm−4, Ayz ∼ 5 × 10−4 cm−4 for the 63Cu isotope. The analysis of the experimental data allows proposing center model as CuZr2+ in the monoclinic ZrO2 lattice. The comparison with photoluminescent data allows assumption that EPR center investigated participate in the light emission process.