  Ionoluminescence (IL) and photoluminescence (PL) of trivalent erbium ions
(Er3+) in Gd2O3 nanopowder host activated with Bi3+ ions has been studied in
order to establish the link between changes in luminescent spectra and
temperature of the sample material. IL measurements have been performed with
H2+ 100 keV ion beam bombarding the target material for a few seconds, while PL
spectra have been collected for temperatures ranging from 20 to 700{\deg}C. The
PL data was used as a reference in determining the temperature corresponding to
IL spectra. The collected data enabled the definition of empirical formula
based on the Boltzmann distribution, which allows the temperature to be
determined with a maximum sensitivity of 9.7 x 10-3 {\deg}C-1. The analysis of
the Er3+ energy level structure in terms of tendency of the system to stay in
thermal equilibrium, explained different behaviors of the lines intensities.
This work led to the conclusion that temperature changes during ion excitation
can be easily defined with separately collected PL spectra. The final result,
which is empirical formula describing dependence of fluorescence intensity
ratio on temperature, raises the idea of an application of method in
temperature control, during processes like ion implantation and some nuclear
applications.
