article posted 28 March 2016
Jana Holubová is an associate professor at Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Czech Republic.
She graduated with a degree in physical chemistry from Faculty of Science, Charles University in Prague, Czech Republic and received PhD degree in inorganic chemistry at University of Pardubice in 1996.
Her research is focused on the structure, thermal behavior and some other physical and chemical properties of chalcogenide and phosphate based glasses.
Structural Investigation and Properties of
Gallium Zinc Phosphate Glasses
Jana Holubova1*, Zdenek Cernosek1, Eva Cernosková2
Phosphate glasses, especially glasses based on zinc-phosphate, are being
intensively studied during recent years because they provide some unique physical
properties compared to silicate glasses, such as low melting temperature, high coefficient
of thermal expansion and low optical dispersion. The introduction of various metal
oxides results in variability of their physical and chemical properties, gallium trioxide
has received attention because of improving chemical durability and of antibacterial
properties. The aim of our work was to study the effect of substitution of zinc by gallium
on some physico- chemical properties of phosphate glasses, as well as on their structure.
The glasses of ternary gallium zinc phosphate system have been prepared by a conventional
melt-quenching method in two compositional series:
(x = 0, 3, 5, 10, 13, 15, 20, 25, 30)
and B: yGa2
(y = 0, 5, 10, 15, 20, 25),
the last one is a metaphosphate profile. The homogeneous glasses were prepared in the
whole concentration regions.
Thermal properties of glasses were studied by differential thermal analysis (DTA) and
thermomechanical analysis (TMA). Addition of Ga2
results in increase of density,
glass transition temperature and microhardness of studied glasses, while the coefficient
of thermal expansion decreases.
The effect of successive replacement of zinc by gallium on basic phosphate structure
has been evaluated using Raman spectroscopy, 31
P MAS and static
Ga MAS NMR was used for monitoring of of changes of gallium
In glasses of series A the coordination of Ga3+
change from six-coordination to
four-coordination with increasing content of Ga, in series B only octahedral coordination
was found. Chemometrical analysis, namely multivariate curve resolution (MCR) and
correlation spectroscopy was also used to obtain detailed information on structure from
Raman scattering and both type of 31
P NMR spectra.
1 Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 532 10 Pardubice, Czech Republic,
2 Joint Laboratory of Solid State Chemistry of Institute of Macromolecular Chemistry of Czech Academy of Sciences, v.v.i., and University of Pardubice, Pardubice, Czech Republic