  Various elastic coefficients of Au2O3 doped PbO-B2O3-SeO2:Er2O3 (PBSE) glass
ceramics were evaluated as functions of Au2O3 content using ultrasonic velocity
measurements. The elastic coefficients and micro-hardness showed a decreasing
tendency with the concentration of Au2O3. Such decrease is attributed to the
increasing concentration of gold metallic particles and [SeO3]2- groups that
acted as modifiers and induced imperfections in these samples. Obtained results
were observed to be consistent with the conclusions drawn from spectroscopic
studies that include X-ray photoelectron spectroscopy (XPS), infrared (IR),
photoluminescence (PL) and positron annihilation (PAL) spectroscopy studies.
Overall, these studies have revealed that even though, the presence of gold
metallic particles is preferable for achieving superior luminescence and
electrical properties, presence of such particles caused to decrease the
elastic coefficients and micro-hardness of these glass ceramics. However, when
the concentration of Au2O3 is increased beyond 0.075 mol%, we have observed a
slight increase of elastic coefficients and micro-hardness.
