Electron Spin Resonance Study of Nd$\text{}^{3+}$ and Er$\text{}^{3+}$ Ions in YAlO$\text{}_{3}$

In this paper we present the results of ESR and photo-ESR measurements on YAlO$\text{}_{3}$(YAP) single crystals and powder samples doped purposely with about 1 at.% Nd$\text{}^{3+}$ and undoped crystals in which Er$\text{}^{3+}$ was observed as residual dopant. The ESR measurements were carried out at X-band spectrometer in 4-300 K temperature range. The photo-ESR was performed at 5 K using a mercury arc lamp. For the Nd$\text{}^{3+}$ doped crystals the intensity of ESR signal decreased about 2 times during illumination conditions. Moreover, the calculations of the g tensor and A hyperfine structure parameters for Nd$\text{}^{3+}$ and Er$\text{}^{3+}$ were carried out.