Sorption and gas sensitive properties of In2O3 based ceramics doped with Ga2O3

In2O3:Ga and In2O3:P-based one-electrode gas sensors: Comparative study

“…According to [32], this fact indicates that the In 2 O 3 grain size decreased while Ga concentration in In 2 O 3 :Ga increased. Results reported by Ratko et al [11] confirm this conclusion. In our experiments we have also observed the decrease of the grain size in the In 2 O 3 :Ga powders.…”

“…For example, for In 2 O 3 :Ga-based sensors during H 2 detection the doping was accompanied by the power change from 130 mW to 180 mW, while for In 2 O 3 :P sensors the power dissipated in the maximum of sensor response has been changing from 130 mW to 260 mW. The same effect was also observed in [11] for In 2 O 3 :Ga-based sensors during detection of CH 4 . An increase of Ga-oxide concentration was being accompanied by the shift of the maximum sensitivity to methane from 400 1C (0% Ga 2 O 3 ) to 520 1C (20% Ga 2 O 3 ).…”

“…In this case, along with two phases of indium oxide such as rhombohedral and cubic, β-Ga 2 O 3 and (Ga, In) 2 O 3 phases may occur. In XRD experiments of Ratko et al [11], who used the same technology of In 2 O 3 :Ga synthesis, the traces of Ga 2 O 3 phase were detected only for samples with 20% Ga 2 O 3 . This means that the In 2 O 3 crystallites remain the dominant phase in the In 2 O 3 :Ga matrix studied in present research.…”

“…The absence of the second phase and strong shift of the peak position indicate that gallium not only incorporates in the In 2 O 3 lattice, but also has high solubility in In 2 O 3. This situation is realistic enough, because according to estimations given in [11], the solubility limit of Ga in In 2 O 3 reaches 11-12%. It was also shown that In 2 O 3 and Ga 2 O 3 in a wide range of composition could form solid solutions [33].…”

“…One should note that there are only a few references which describe synthesis and study of In 2 O 3 :Ga and In 2 O 3 :P-based ceramics [10][11][12][13][14][15]. It was indicated there that additives such as gallium and phosphorus might be useful for optimization of gas sensing properties of In 2 O 3 -based ceramics.…”