**3.3. Ferroelectric and pyroelectric parameters**

Figure 10 shows the temperature dependence of the remanent polarization (*Pr*), which has been obtained from the pyroelectric current dependence *iP*(*T*) using equation 3. It can be noted that there is an important influence of the barium concentration on the *Pr* values. At room temper‐ ature, an increase of *Pr* is observed for the lower barium concentration (x ≤ 30 at%); above 30 at%, *Pr* decreases. These results are in agreement with the *Pr* behaviour, which has previously been discussed in relation to the hysteresis loops (*P*-*E* dependence).

**Figure 10.** Temperature dependence of the remanent polarization (*Pr*) for the studied compositions.


**Table 3.** Values of the remanent polarization (*Pr*), the pyroelectric coefficient (*p*) and the current response parameter (*RV*).

Table 3 shows the values for the remanent polarization (*Pr*), the pyroelectric coefficient (*p*) and the current response parameter (*RV*), at room temperature, for the studied samples. The last two parameters were obtained using equations 4 and 5, respectively. The SBBN-30 sample shows the better pyroelectric parameter. The values for the pyroelectric parameters are analogous to previous reports in other Aurivillius materials [24]. However, these are lower than those for conventional lead-based ferroelectric systems [38-39]. Further researches are in progress.
