Home – Home – Jornals – Journal of Structural Chemistry 2012 number 4

The crystals of zinc tungstate (ZTO) are a radiation-hardened matrix and are widely used as scintillators for high energy radiation. Therefore, it is interesting to study the possibility of introducing gadolinium ions into this structure to obtain the lasing properties. In order to activate ZTO crystals by gadolinium ions, 0.5 mol.% of Gd₂O₃ is added to the load. High-quality large crystals of ZTO are produced. The spectra of optical transmission, luminescence excitation, and luminescence are measured at room temperature. It is shown that the introduction of gadolinium ions does not result in a shift of the main luminescence band of the ZTO crystals. The analysis of the ESR spectra and their modeling enables the calculation of spin-Hamiltonian parameters. It is shown that the observed spectrum depends on the state of Gd³⁺ ions with S = 7/2 and is well described by the spin-Hamiltonian parameters g_x = 1.9835, g_y = 1.9685, g_z = 1.9688 and D = 644.88 Gs, E = 161.49 Gs. Directions of the principal values of the D tensor are determined; they reflect a strong distortion of the nearest-neighbor oxygen environment.