ИСТИНА

All samples under investigation showed similar form of signals with dif-ferent intensities. Fig.1 shows EPR spectrum of the sample with the ratio N/Ti=2. As one can see in Fig. 1, an asymmetric signal is observed at room temperature. The parameters of the sig-nal, calculated during a computer simu-lation, were as follows: g-tensor - g1 = 2.009, g2 = 2.0052, g3 = 2.0036; line width - ΔH1 = 3.6 G, ΔH2 = 3.1 G, ΔH3 = 3.3 G, and hyperfine tensor values - A1 = 2.3 G, A2 = 3.1 G, A3 = 32.0 G. According to the [2,3], this signal corre-sponds to N· radicals. The double peak is observed in the EPR spectrum (Fig.1). We assume that such splitting can be due to different positions of N atom in TiO2 structure. According to the [2], N atom in N-TiO2 is situated either in the interstitial (O - N· - Ti) or substitutional (Ti - N· - Ti) positions. At low temperatures new EPR signal is detected, as you can see in Fig.2. The parameters of the signal, calculated during the computer simulation.