## 3 Results and Discussion
### Gas-Sensing Properties
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Thin Film**} & **Annealing** & \multirow{2}{*}{**Phase**} & \multirow{2}{*}{**20**} & \multirow{2}{*}{**(hkl)**} & \multirow{2}{*}{
\begin{tabular}{c} **d** \\ **(nm)** \\ \end{tabular} } & \multirow{2}{*}{**d\({}_{\mathrm{PDF}}\)**} & \multirow{2}{*}{**D (nm)**} & \multirow{2}{*}{**PDF**} \\  & **Temperature** & & & & & & \\ \hline \multirow{4}{*}{**TiO\(\mathrm{x}^{\mathrm{ORC}}\)**} & as deposited & amorphous & - & - & - & - & - \\ \cline{2-8}  & 200 \({}^{\circ}\)C & amorphous & - & - & - & - & - \\ \cline{2-8}  & 400 \({}^{\circ}\)C & amorphous & - & - & - & - & - \\ \cline{2-8}  & 600 \({}^{\circ}\)C & amorphous & - & - & - & - & - \\ \hline \multirow{4}{*}{**TiO\(\mathrm{x}^{\mathrm{ORC}}\)**} & as deposited & amorphous & - & - & - & - & - \\ \cline{2-8}  & 200 \({}^{\circ}\)C & Ti & 35.53\({}^{\circ}\) & (100) & 0.2524 & 0.2555 & 11.4 & 65-3362 \\  & Ti & 38.67\({}^{\circ}\) & (002) & 0.2327 & 0.2342 & 10.1 & 65-3362 \\ \cline{2-8}  & 400 \({}^{\circ}\)C & TiO\({}_{2}\)-anatase & 25.16\({}^{\circ}\) & (101) & 0.3536 & 0.3520 & 10.8 & 21-1272 \\  & Ti & 35.44\({}^{\circ}\) & (100) & 0.2531 & 0.2555 & 13.5 & 65-3362 \\  & Ti & 38.56\({}^{\circ}\) & (002) & 0.2333 & 0.2342 & 11.2 & 65-3362 \\ \cline{2-8}  & 600 \({}^{\circ}\)C & TiO\({}_{2}\)-anatase & 25.23\({}^{\circ}\) & (101) & 0.3526 & 0.3520 & 21.1 & 21-1272 \\  & TiO\({}_{2}\)-anatase & 32.48\({}^{\circ}\) & (020) & 0.2755 & 0.2749 & 20.0 & 21-1236 \\  & Ti & 35.50\({}^{\circ}\) & (100) & 0.2527 & 0.2555 & 19.7 & 65-3362 \\  & Ti & 38.68\({}^{\circ}\) & (002) & 0.2326 & 0.2342 & 14.5 & 65-3362 \\  & TiO\({}_{2}\)-anatase & 48.41\({}^{\circ}\) & (200) & 0.1879 & 0.1892 & 12.8 & 21-1272 \\  & TiO\({}_{2}\)-anatase & 48.91\({}^{\circ}\) & (312) & 0.1861 & 0.1852 & 15.8 & 65-2448 \\  & TiO\({}_{2}\)-anatase & 53.82\({}^{\circ}\) & (105) & 0.1702 & 0.1700 & 16.1 & 21-1272 \\  & TiO\({}_{2}\)-anatase & 55.12\({}^{\circ}\) & (211) & 0.1665 & 0.1665 & 19.6 & 21-1272 \\  & TiO\({}_{2}\)-anatase & 62.35\({}^{\circ}\) & (204) & 0.1488 & 0.1408 & 13.5 & 21-1272 \\  & Ti & 66.13\({}^{\circ}\) & (002) & 0.1412 & 0.1409 & 12.3 & 51-0631 \\  & TiO\({}_{2}\)-anatase & 70.27\({}^{\circ}\) & (220) & 0.1338 & 0.1338 & 19.6 & 21-1272 \\  & TiO\({}_{2}\)-anatase & 75.29\({}^{\circ}\) & (215) & 0.1261 & 0.1265 & 13.6 & 21-1272 \\ \hline \hline \end{tabular} Designations: d—interplanar distance, d\({}_{\mathrm{PDF}}\)—standard interplanar distance, D—average crystallites size, PDF—powder diffraction files (card).  
\end{table} 
Table 3: Results of GIXRD measurements for TiOx thin films deposited under oxygen-rich (ORC), and oxygen-deficient (ODC) conditions, and additionally annealed at 200 \({}^{\circ}\)C, 400 \({}^{\circ}\)C, and 600 \({}^{\circ}\)C.  
parameters were not determined because of the mentioned overflow. The sensor response of the coating was defined using the following equation:  
\[SR=\frac{R_{g}}{R_{a}}.100\% \tag{1}\]  
where \(SR\) is the sensor response, \(R_{g}\) is the maximum resistance of the coating upon exposure to hydrogen, and \(R_{a}\) is the resistance of the coating upon exposure to air. Figure 8: Changes in the resistance of the TiOx coating deposited under ORC after exposure to hydrogen gas. Figure 9: _Cont._  
The response time was defined as the time in which the resistivity increased to 90% of the difference between the base resistance and the maximal value after the introduction of the reducing gas. The recovery time was defined as the time in which the resistivity of the coating decreased to 90%. The sensor response of the \(\mathrm{TiOx}^{\mathrm{ODC}}\) coating was found to be the highest for those annealed at 300 \({}^{\circ}\)C and 400 \({}^{\circ}\)C. It is worth noting that the change in resistance was as much as eight times greater. The response time was in the range of 40 min to 56 min. Recovery time increased with increasing annealing temperature, from a value of 1.5 to 24 min.