## 3 Results and Discussion
For both ceramic samples, 100 kHz curves from \(\varepsilon_{r}-T\) were simulated, and values calculated for the diffusion co-efficient using Equation (2) for BNKLBT and BNKMBT ceramics were 1.617 (Figure 4c) and 1.753 (Figure 4f), respectively. Figure 5 shows the ferroelectric analysis (\(P-E\)) of BNKLBT and BNKMBT ceramic samples at room temperature with a frequency 10 Hz under a critical electric field of 100 kV/cm. Both \(P-E\) loops are slimmer, which is a characteristic of relaxor ferroelectrics compared to normal ferroelectrics that are widely open on the electric field axis. The values entered in Table 2 were calculated by using the following relations [15]:  
\[W_{rec}=\int_{P_{T}}^{Pmax}{Edp} \tag{3}\]  
\[W_{st}=\int_{0}^{Pmax}{Edp} \tag{4}\]  
\[\eta=\frac{W_{rec}}{W_{st}}\times 100 \tag{5}\]  
where the values of \(P_{max}\), \(P_{r}\), and \(E\) were obtained from measured \(P-E\) loops. The maximum polarization (\(P_{max}\)) for the BNKLBT ceramic was 21.24 \(\mu\)C/cm\({}^{2}\), while for the BNKMBT  
Figure 4: Temperature-dependent dielectric constant (\(\varepsilon_{r}\)) of (**a**) the BNKLBT ceramic, and (**d**) the BNKMBT ceramic. Temperature-dependent dielectric loss (tan\(\delta\)) of (**b**) the BNKLBT ceramic and (**e**) the BNKMBT ceramic. Diffusion coefficient (\(\gamma\)) measurements by \((1/\epsilon-1/\epsilon_{\rm m})\) vs. \((1/\Gamma-1/T_{\rm m})\) plots of (**c**) the BNKLBT ceramic, and (**f**) the BNKMBT ceramic. c ceramic the \(P_{max}\) was 17.71 \(\upmu\)C/cm\({}^{2}\) at 100 kV/cm. Dielectric capacitive analysis in terms of stored (\(W_{ST}\)) and recoverable (\(W_{rec}\)) charge densities and energy conversion efficiency (\(\eta\)) of both ceramic samples are presented in Table 2 depending on maximum polarization (\(P_{max}\)) and remnant polarization (\(P_{r}\)) for an electric field of 100 kV/cm. The \(W_{rec}\), \(W_{ST}\) and \(\eta\) of the fabricated BNKLBT ceramic were 0.8525 J/cm\({}^{3}\), 1.062 J/cm\({}^{3}\) and 80.27%, respectively, while for the BNKMBT ceramic were 0.7295 J/cm\({}^{3}\), 0.8855 J/cm\({}^{3}\) and 82.38%, respectively. It was seen that high entropy BNKLBT and BNKMBT ceramics showed relatively high energy conversion efficiencies >80%, which is associated with the relaxor ferroelectric behavior of the ceramics. The dielectric energy storage performance of these high-entropic ceramics is not as high as traditional perovskites [25; 26; 27], but much better as reported high entropic ceramic systems (Table 3). Low dielectric loss <0.3, even at high temperature, (300 \({}^{\circ}\)C) indicates the existence of highly dense ceramics, which suggests there are no holes or cracks, as was evident from the SEM analysis. Low dielectric loss also results in the low leakage current of the ceramics [28], resulting in better ferroelectric and dielectric capacitive performance of the ceramics. A comparison among the different reported high-entropic ceramics and our results is shown in Table 3. Our results clearly indicate the potential of the high-entropy ceramics for dielectric capacitors. \begin{table}
\begin{tabular}{c c c c c c} \hline
**Entropic** & \(P_{max}\) & \(P_{r}\) & \(W_{rec}\) & \(W_{ST}\) & \(\eta\) \\
**Ceramics** & \(\upmu\)**C/cm\({}^{2}\)** & \(\upmu\)**C/cm\({}^{2}\)** & **J/cm\({}^{3}\)** & **J/cm\({}^{3}\)** & **\%** \\ \hline
**BNKLBT** & 21.24 & 4.19 & 0.8525 & 1.062 & 80.27 \\ \hline
**BNKMBT** & 17.71 & 3.12 & 0.7295 & 0.8855 & 82.38 \\ \hline \end{tabular}
\end{table} 
Table 2: Dielectric capacitive performance of high-entropy BNKLBT and BNKMBT ceramics. Figure 5: Ferroelectric analysis by polarization vs. electric field (\(P\)\(-\)\(E\) loops) for dielectric capacitive measurements of (**a**) the BNKLBT ceramic and (**b**) the BNKMBT ceramic. Temperature dependent ferroelectric analysis of the prepared BNKLBT and BNKMBT ceramics is illustrated in Figure 6 (a and c respectively).