full-matrix least-square technique using anisotropic thermal
parameters for non-hydrogen atoms and a riding model for
hydrogen atoms.
The crystals were placed in a standard quartz cell (l = 1 cm) that
was excited with xenon lamp at 450 W. The registration was
carried out with ‘‘on reflection” geometry.
The triboluminescence of crystals (150–200 mg) was achieved
in a cylindrical steel cell having quartz window at the bottom.
For the TL excitation, 4-blade TPFE rod rotating at 1000 rpm was
used [16,17]. In some cases, in recording TL spectra, argon was feed
in cell at 10–15 ml/s using a tube. The cell was tightly closed to
produce excess pressure.
The radioluminescence of crystals was excited with the use of
microfocus X-ray tube BMS-1 equipped with Cu Ka anode up to
45 kV [9].
The TL and PL spectra, as well as lifetimes of the excited-state
Ln3+ ions were recorded by means of Fluorolog-3 (Horiba Jobin
Yvon) spectrofluorometer equipped with photomultiplier tube
Hamamatsu R928P. The RL spectra were recorded on a Aminco–
Bowman J4-8202 spectrofluorometer equipped with a Hamamatsu
R3896 detector.