Abstract: Dielectric responses of as-grown PbWO₄ single crystal doped with Gd³⁺ ion were measured. Experimental results show that typical dielectric relaxation
phenomena exist in the crystal. There is one Debye-type dielectric peak (α) in the heating cycle from 40℃ up to 600℃, while another peak (β) in the cooling cycle. Activation energies of the two peaks(α and β) are 0.50±0.01 eV and 0.51±0.02 eV, with a frequency factor 1.44×10⁹s^-1 and 2.44×10⁶s^-1 respectively. Both peaks can
be explained by the presence of dipole complexes formed by the doped Gd³⁺ ions coupled with Pb vacancies and interstitial oxysen respertively. The correlation between the dielectric and scintillation properties was discussed.

Key words: dielectric relaxation, Gd-doped PbWO4, dipole complexes