Journal of Science: Advanced Materials and Devices xxx (xxxx) xxx Contents lists available at ScienceDirect Journal of Science: Advanced Materials and Devices journal homepage: www.elsevier.com/locate/jsamd Original Article Microstructure tailoring for enhancing the energy storage performance of 0.98[0.6Ba(Zr0.2Ti0.8)O3-0.4(Ba0.7Ca0.3)TiO3]0.02BiZn1/2Ti1/2O3 ceramic capacitors A.R Jayakrishnan a, Penna Venkata Karthik Yadav a, J.P.B Silva b, **, K.C Sekhar a, * a b Department of Physics, School of Basic and Applied Sciences, Central University of Tamil Nadu, Thiruvarur, 610 005, India Centro de Fısica das Universidades Minho e Porto (CF-UM-UP), Campus de Gualtar, 4710-057, Braga, Portugal a r t i c l e i n f o a b s t r a c t Article history: Received September 2019 Received in revised form December 2019 Accepted December 2019 Available online xxx In this work, we introduce a new approach to enhance the energy storage properties of 0.98 [0.6Ba(Zr0.2Ti0.8)O3-0.4(Ba0.7Ca0.3)TiO3]-0.02BiZn1/2Ti1/2O3 [BCZT-BZ] ceramic capacitors via tuning the microstructure through the sintering time The x-ray diffraction (XRD) analysis confirmed the formation of BCZT-BZ solid solution without any secondary phase It is observed that the rhombohedral and tetragonal phases co-exist in BCZT-BZ samples sintered at different time periods, except the one sintered for 11 h, where the rhombohedral and pseudocubic phases co-exist The energy dispersive x-ray spectroscopy (EDS) revealed the presence of the elements constituting the BCZT-BZ samples The variation of the grain size with the sintering time is explained based on the coalescence process and the Ostwald ripening mechanism A strong correlation was observed between the ferroelectric properties and the microstructure The sample sintered for 11 h with pseudocubic nature and small grain size shows a slim P-E loop owing to a high recoverable energy density (2.61 J/cm3) and a high efficiency (91%) at an electric field of 150 kV/cm The observed recoverable energy density was found to 13 times higher than that reported for bulk BCZT These findings suggest that the present BCZT-BZ ceramics are attractive materials for the energy storage capacitor applications © 2019 The Authors Publishing services by Elsevier B.V on behalf of Vietnam National University, Hanoi This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) Keywords: Ceramics Relaxor ferroelectrics Lattice distortion Grain size Recoverable energy Introduction Recently, (1-x)Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 ceramics with outstanding dielectric, ferroelectric and piezoelectric properties are considered a typical lead free electroceramic material and therefore, have been also investigated for promising application as energy storage capacitors [1,2] For instance, Puli et al reported an energy storage density of 0.94 J/cm3 with an efficiency of 72% in (1x)Ba(Zr0.2Ti0.8)O3-x(Ba0.7Ca0.3)TiO3 ceramic capacitors at an electric field of 170 kV/cm [3] However, real-world applications actually require materials with an energy storage efficiency greater than 90% [4] For enhancing the energy storage efficiency, we need to improve the difference (DP ¼ PmePr) between the remanent (Pr) * Corresponding author ** Corresponding author E-mail addresses: josesilva@fisica.uminho.pt (J.P.B Silva), sekhar.koppole@ gmail.com (K.C Sekhar) Peer review under responsibility of Vietnam National University, Hanoi and the maximum polarization (Pm), and the dielectric breakdown strength (DBS) [5,6] as well Thus, it may be an appropriate strategy to induce a dielectric relaxor behavior in conventional ferroelectric materials as the relaxor ferroelectrics possess slim P-E loops [5,6] Different approaches, such as doping of rare earth metals in ferroelectric materials, the formation of ferroelectric-paraelectric (SrTiO3) solid solutions and the coupling of ferroelectrics with semiconductors (ZnO, MgO) have been adopted to improve the relaxor behavior of the conventional ferroelectric materials [7,8,9] On the other hand, the bismuth-based perovskites BiMO3 (with M ¼ Sn, In, Fe, Yb, Zn1/2Ti1/2, Ni1/2Ti1/2, Zn1/2Sn1/2, Mg1/2Ti1/2, Li1/2Nb1/ 2, etc.) have a large ferroelectric polarization, a large dielectric constant and great piezoelectric coefficients, but they are very unstable under ambient conditions [10,11] Therefore, researchers have made an attempt to form solid solutions of BiMO3 with the conventional ferroelectric materials in the form of binary or ternary oxides in order to utilize their outstanding ferro- and piezoelectric properties [10,11] The inclusion of a small amount of bismuthbased perovskites in ferroelectric materials usually decreases the tetragonal distortion and broadens the ferroelectric-paraelectric https://doi.org/10.1016/j.jsamd.2019.12.001 2468-2179/© 2019 The Authors Publishing services by Elsevier B.V on behalf of Vietnam National University, Hanoi This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) Please cite this article as: A.R Jayakrishnan et al., Microstructure tailoring for enhancing the energy storage performance of 0.98[0.6Ba(Zr0.2Ti0.8) O3-0.4(Ba0.7Ca0.3)TiO3]-0.02BiZn1/2Ti1/2O3 ceramic capacitors, Journal of Science: Advanced Materials and Devices, https://doi.org/10.1016/ j.jsamd.2019.12.001 A.R Jayakrishnan et al / Journal of Science: Advanced Materials and Devices xxx (xxxx) xxx phase transition [10] Moreover, it is observed that ferroelectricBiMO3 solid solutions are good relaxor ferroelectric materials Usually, the relaxor behavior arises when the translational symmetry, which is essential for the ferroelectric long-range order, is disturbed by the doping [12] causing the non-homogenous stoichiometry in nanoscale regions, ascribed as polar nano regions (PNRs) [12] It has been also shown that the translational symmetry can be disturbed by modifying the microstructure, especially by the reduction of the grain size to nanoscale and thus, the same relaxor behavior can be induced by the microstructure control [12,13] In view of this, we proposed a new kind of relaxor ferroelectric material based on the 0.6Ba (Zr0.2Ti0.8)O3-0.4(Ba0.7Ca0.3) TiO3eBiZn1/2Ti1/2O3 solid solution We have chosen BiZn1/2Ti1/2O3 because of its very high ionic polarization of 153 mC/cm2 and 0.6Ba(Zr0.2Ti0.8)O3-0.4(Ba0.7Ca0.3)TiO3 due to its optimum energy storage properties [11,14] The addition of a small amount of BiZn1/ 2Ti1/2O3 in 0.6Ba(Zr0.2Ti0.8)O3-0.4(Ba0.7Ca0.3)TiO3 can form the PNRs due to the difference in the valence states and the ionic radii between Bi3ỵ and Ba2ỵ as well as Zn2ỵ and Ti4ỵ ions These PNRs hinder the long-range ferroelectric order and improve the relaxor behavior [15] Further, we have made an attempt to improve the relaxor behavior of 0.6Ba(Zr0.2Ti0.8)O3-0.4(Ba0.7Ca0.3)TiO3eBiZn1/ 2Ti1/2O3 ceramics through the grain size tuning by varying the sintering time, thus enhancing their energy storage performance SigmaeAldrich) were used as the starting materials and weighed according to stoichiometric ratio The reagents were then mixed and grinded using a ball miller and subsequently calcined at 1000 C for h The calcined powder was pressed into pellets and then, sintered at 1200 C for h and allowed to cool down to room temperature naturally These single sintered pellets were sintered for the second time at 1200 C by varying the sintering time from to 13 h 2.2 Structural characterization An Empyrean X-ray diffractometer (Malvern Panalytical, The Netherlands) with Ni-filtered CuKa radiation of wavelength 1.54 Å was utilized to record the x-ray diffraction patterns (XRD) of the ceramic samples The lattice parameters of the different samples were determined using a lattice refinement program called CellCalc [16,17] The surface morphology and the chemical composition were analyzed using a field emission scanning electron microscope (FESEM) (Tescan Mira 3, Australia) with a build-in energy dispersive x-ray spectroscopy (EDS) function Experimental 2.3 Ferroelectric measurements 2.1 Ceramic preparation A highly conductive silver paste was coated on the smooth surfaces of the pellets and the ferroelectric properties were investigated in the metal-insulator-metal (MIM) configuration The polarization-electric field (P-E loop) hysteresis curves were recorded using P-E loop tracer (Marine India), built on the modified Sawyer and Tower circuit [18] The P-E loops were recorded at different electric fields in the range from 30 kV/cm to 150 kV/cm A conventional solidestate reaction was utilized to prepare the 0.98[0.6Ba(Zr0.2Ti0.8)O3-0.4(Ba0.7Ca0.3)TiO3]-0.02BiZn1/2Ti1/2O3 [BCZT-BZ] ceramics High purity BaCO3 (99%, SigmaeAldrich), TiO2 (99%, SigmaeAldrich), CaCO3 (98.5%, Merck - Emplura), ZrO2 (97%, LobaChemie), Bi2O3 (99%, SigmaeAldrich) and ZnO (99%, Fig (a) XRD patterns of BCZT-BZ ceramics sintered at different time periods; (b) Extended scan near 2q z 45 Please cite this article as: A.R Jayakrishnan et al., Microstructure tailoring for enhancing the energy storage performance of 0.98[0.6Ba(Zr0.2Ti0.8) O3-0.4(Ba0.7Ca0.3)TiO3]-0.02BiZn1/2Ti1/2O3 ceramic capacitors, Journal of Science: Advanced Materials and Devices, https://doi.org/10.1016/ j.jsamd.2019.12.001 A.R Jayakrishnan et al / Journal of Science: Advanced Materials and Devices xxx (xxxx) xxx Results and discussion 3.1 Microstructural properties Fig 1(a) shows the XRD patterns of the BCZT-BZ ceramics sintered at various time periods from to 13 h All the samples exhibit a single perovskite phase of BCZT without any impurity phase [JCPDS file no: 05e0626, 85e0368] This suggests the formation of the solid solution of BCZT and BZ Further, the reflection near 2q z 45 splits into (002) and (200) reflection planes as shown in Fig 1(b) This confirms the presence of the tetragonal phase (JCPDS file no: 05e0626, P4mm) in all the samples except in the one Table Effect of sintering time on the lattice parameters, the crystallite size and the tetragonality of the BCZT-BZ ceramics Sintering time (hrs) a¼b (Å) C (Å) c/a ratio Crystallite size (nm) 11 13 3.9916 3.9941 3.9950 3.9972 3.9915 3.9967 4.0028 4.0081 4.0122 4.0291 4.0011 4.0251 1.0028 1.0035 1.0043 1.0079 1.0024 1.0071 41 43 49 57 34 38 c n ¼( À 1)*100 a 0.28 0.35 0.43 0.79 0.24 0.71 sintered for 11 h Furthermore, the reflection at 2q z 66 splits into two corresponding to the (220) and (202) planes of the rhombohedral phase of BCZT (JCPDS file no: 85e0368, R3m) This is in good agreement with the fact that BCZT exhibits a morphotropic phase boundary such as the co-existence of both the rhombohedral and the tetragonal phases at room temperature [14,19] The effect of sintering time on the lattice parameters, the tetragonality (i.e the c/a ratio), the crystallite size and the tetragonal distortion (n ¼ (ac À 1)*100) is given in Table The low value of tetragonal distortion and the absence of the peak splitting for the sample sintered for 11 h suggest the presence of a pseudocubic phase rather than the tetragonal one, possibly due to the small grain size [13] In order to evaluate the surface morphology of the ceramics, field emission scanning electron microscopy (FESEM) images were recorded and the results are shown in Fig All the samples show the dense microstructure without any pores The variation of the average grain size with the sintering time is shown in Fig 2(f) The variation of the grain size with the sintering time periods is the same as that of the crystallite size as evidenced from the XRD analysis (Table 1) The slight increase in grain size with the increase of the sintering time up to h can be attributed to the coalescence process With further increase of sintering time to h, the sharp increase in grain size can be attributed to the dominance of the Ostwald ripening mechanism [20,21] Further, too long period of Fig FESEM images of BCZT-BZ ceramics sintered for (a) h; (b) h; (c) h; (d) 11 h; (e) 13 h; (f) Average grain size as a function of the sintering time Please cite this article as: A.R Jayakrishnan et al., Microstructure tailoring for enhancing the energy storage performance of 0.98[0.6Ba(Zr0.2Ti0.8) O3-0.4(Ba0.7Ca0.3)TiO3]-0.02BiZn1/2Ti1/2O3 ceramic capacitors, Journal of Science: Advanced Materials and Devices, https://doi.org/10.1016/ j.jsamd.2019.12.001 A.R Jayakrishnan et al / Journal of Science: Advanced Materials and Devices xxx (xxxx) xxx 30 kV/cm It is found that the saturation polarization (Ps) and the coercive field (Ec) follow a similar pattern as that of the tetragonal distortion (n) and of the grain size (G) [ Fig 4(b)] with the sintering time This is in good agreement with the modified LGD theory It relates Ps, n, and G, as follows [22]: P s f Gfn Fig EDS spectrum of the BCZT-BZ sample sintered for 11 h sintering (over 11 h) may lead to excessive grain growth, so that the grains become unstable and decompose into tiny ones as virtually evidenced in Fig 2(d) [20] With further increase of the sintering time to 13 h, the coalescence process may be revisited and the grain size slightly increases (Fig 2(e)) [21] The EDS spectrum of BCZT-BZ sample sintered at 11 h shown in Fig confirms the presence of all the constituting elements, such as Ba, Ca, Zr, Ti, Bi, Zn, and O 3.2 Ferroelectric and energy storage properties Fig 4(a) displays the P-E loops of the BCZT-BZ ceramics sintered at different sintering time periods under an electric field of (1) From the XRD and FESEM results, it is clear that the ceramic sample sintered for 11 h has the lowest value of G and n, and consequently a low value of Ps Furthermore, the sample sintered for 11 h exhibited a slim P-E loop with a small value of the remanent polarization (Pr) This slim behavior can be correlated to the pseudocubic nature of its structure and its smallest grain size The origin of the pseudocubic structural nature is usually attributed to the existence of microdomains or PNRs rather than macroscopic domains [18] The size of these microdomains or PNRs is small compared to the macroscopic domains Hence, they respond much faster to the external field than the macroscopic domain resulting in a slim P-E loop [23,24] Further, the decrease in the grain size weakens the long-range ferroelectric order and induces the relaxor behavior due to the short-range forces Furthermore, the translational symmetry is disturbed with the increase of grain boundaries due to the grain size reduction and the material thus behaves like relaxor ferroelectrics [12] Consequently, the P-E loop shows the slim behavior with low Pr Since the domain size is proportional to the square of the grain size, the formation of single domains rather than multiple ones becomes more probable with the reduction of the grain size In this case, low Pr is expected due to the low contribution of domain walls and domain switching due to pinning/clamping by grain boundaries [18] Thus, a slim behavior is expected in ceramics with the lowest grain size The recoverable energy density (Wr), the energy loss (Wl) and the efficiency (h) of the samples were calculated from P-E Fig (a) P-E loops of the BCZT-BZ ceramics sintered at different time periods; (b) Ps, n, and G as a function of the sintering time; (c) Schematic representation of the calculation of energy storage properties; (d) Wr, Wl, and h as a function of the sintering time Please cite this article as: A.R Jayakrishnan et al., Microstructure tailoring for enhancing the energy storage performance of 0.98[0.6Ba(Zr0.2Ti0.8) O3-0.4(Ba0.7Ca0.3)TiO3]-0.02BiZn1/2Ti1/2O3 ceramic capacitors, Journal of Science: Advanced Materials and Devices, https://doi.org/10.1016/ j.jsamd.2019.12.001 A.R Jayakrishnan et al / Journal of Science: Advanced Materials and Devices xxx (xxxx) xxx Fig (a) High field P-E loops of the BCZT-BZ ceramics sintered for 11 h; (b) Comparison of the recoverable energy density of our work with those of other reported BCZT ceramics hysteresis loops as shown in Fig 4(c) based on the following equations [25e27]: Wr ¼ ð Pmax E:dP (2) Pr where Pr is the remanent polarization and Pmax is the maximum polarization The area of the hysteresis loop represents the energy loss (Wl) Further, the energy storage efficiency of the capacitor based on ceramics sintered at different time periods were calculated using the following formula [25e27]: h¼ W Wr ỵ Wl 100 (3) and the results are shown in Fig 4(d) Since, the sample sintered for 11 h possesses a high recoverable energy density, a low loss and a high efficiency at 30 kV/cm, it has been chosen for the study of the energy storage properties at higher electric fields The electric field dependence of the P-E loops of the sample sintered for 11 h is shown in Fig 5(a) The values of the recoverable energy density and the energy storage efficiency are found to be 2.61 J/cm3 and 91%, respectively, at an electric field of 150 kV/cm The comparison of Wr of the BCZT-BZ ceramics sintered for 11 h with that of other BCZT based ceramic capacitors is given in Fig 5(b) and it is found to be of 3e13 times higher than the reported values [3,26e30] Therefore, the BCZT-BZ ceramics sintered for 11 h can be considered the most promising candidate for the energy storage applications Currently, most of the investigations are focused on the improvement of the energy storage density and the efficiency However, for the practical implementation of energy storage capacitors, other aspects like charging and discharging time, fatigue behavior, temperature stability and lifetime are also important which need to be addressed Therefore, studies on these aspects can be taken as a future scope of the works Conclusion We have shown that the energy storage properties of 0.98 [0.6Ba(Zr0.2Ti0.8)O3-0.4(Ba0.7Ca0.3)TiO3]-0.02BiZn1/2Ti1/2O3 ceramic capacitors can be tuned through the modification of the sample microstructure The formation of the 0.98[0.6Ba(Zr0.2Ti0.8)O30.4(Ba0.7Ca0.3)TiO3]-0.02BiZn1/2Ti1/2O3 solid solution, confirmed from the XRD and FESEM analyses, revealed that the sintering time has had a significant impact on the morphology The grain size variation with the sintering time was explained based on the coalescence and the Ostwald ripening mechanism The smallest grain size and the presence of the pseudocubic structural nature in the sample sintered for 11 h were found to weaken the long-range ferroelectric order and favor the relaxor behavior This led to a slim P-E loop and consequently the enhanced energy storage performance The present 0.98[0.6Ba (Zr0.2Ti0.8)O3-0.4(Ba0.7Ca0.3) TiO3]-0.02BiZn1/2Ti1/2O3 ceramics sintered for 11 h exhibit a very high recoverable energy density (2.61 J/cm3) and a high efficiency (91%) at 150 kV/cm Our study has shown that the ferroelectricBiMO3 solid solutions are a promising candidate for energy storage applications Declaration of Competing Interest The authors declare that there is no conflict of interests Acknowledgements The work was supported by (i) DST-SERB, Govt of India through Grant Nr ECR/2017/000068 and (ii) UGC through Grant Nr F.4e5(59-FRP/2014(BSR)) The author A R Jayakrishnan is thankful to Central University of Tamil Nadu, India for his Ph.D fellowship J P B S is grateful for the financial support by the Portuguese Foundation for Science and Technology in the framework of the Strategic Funding UID/FIS/04650/2019 References s, P.B Tavares, K.C Sekhar, K Kamakshi, J Agostinho [1] J.P.B Silva, E.C Queiro Moreira, A Almeida, M Pereira, M.J.M Gomes, Ferroelectric phase transitions studies in 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 ceramics, J Electroceram 35 (2015) 135e140 [2] T.T.M Phan, N.C Chu, V.B Luu, H.N Xuan, D.T Pham, I Martin, P Carriere, Enhancement of polarization property of silane-modified BaTiO3 nanoparticles and its effect in increasing dielectric property of epoxy/BaTiO3 nanocomposites, J Sci.: Adv Mater Devices (2016) 90e97 [3] V.S Puli, D.K Pradhan, D.B Chrisey, M Tomozawa, G.L Sharma, J.F Scott, R.S Katiyar, Structure, dielectric, ferroelectric, and energy density properties Please cite this article as: A.R Jayakrishnan et al., Microstructure tailoring for enhancing the energy storage performance of 0.98[0.6Ba(Zr0.2Ti0.8) O3-0.4(Ba0.7Ca0.3)TiO3]-0.02BiZn1/2Ti1/2O3 ceramic capacitors, Journal of Science: Advanced Materials and Devices, https://doi.org/10.1016/ j.jsamd.2019.12.001 A.R Jayakrishnan et al / Journal of Science: Advanced Materials and Devices xxx (xxxx) xxx [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] of (1-x) BZT-x BCT ceramic capacitors for energy storage applications, J Mater Sci 48 (2013) 2151e2157 Q Abbas, R Raza, I Shabbir, A.G Olabi, Heteroatom doped high porosity carbon nanomaterials as electrodes for energy storage in electrochemical capacitors: a review, J Sci.: Adv Mater Devices (2019) 341e352 M Zhou, R Liang, Z Zhou, X Dong, Novel BaTiO3-based lead-free ceramic capacitors featuring high energy storage density, high power density, and excellent stability, J Mater Chem C (2018) 8528e8537 €rtner, K.C Sekhar, M Pereira, J.P.B Silva, J.M.B Silva, M.J.S Oliveira, T Weinga M.J.M Gomes, High-performance ferroelectric-dielectric multilayered thin films for energy storage capacitors, Adv Funct Mater (2018) 1807196 X Chou, J Zhai, H Jiang, X Yao, Dielectric properties and relaxor behavior of rare-earth (La, Sm, Eu, Dy, Y) substituted barium zirconium titanate ceramics, J Appl Phys 102 (2007), 084106 A Jain, A.K Panwar, A.K Jha, Effect of ZnO doping on structural, dielectric, ferroelectric and piezoelectric properties of BaZr0.1Ti0.9O3 ceramics, Ceram Int 43 (2017) 1948e1955 G Liu, L Zhang, Q Wu, Z Wang, Y Li, D Li, H Liu, Y Yan, Enhanced energy storage properties in MgO-doped BaTiO3 lead-free ferroelectric ceramics, J Mater Sci Mater Electron 29 (2018) 18859e18867 N Raengthon, H.J Brown-Shaklee, G.L Brennecka, D.P Cann, Dielectric properties of BaTiO3-Bi(Zn1/2Ti1/2)O3-NaNbO3 solid solutions, J Mater Sci 48 (2013) 2245e2250 S Dwivedi, T Pareek, S Kumar, Structure, dielectric, and piezoelectric properties of K0.5Na0.5NbO3-based lead-free ceramics, RSC Adv (2018) 24286 C Ziebert, H Schmitt, J.K Krüger, A Sternberg, K.H Ehses, Grain-size-induced relaxor properties in nanocrystalline perovskite films, Phys Rev B 69 (2004) 214106 G Arlt, D Hennings, G de With, Dielectric properties of fine-grained barium titanate ceramics, J Appl Phys 58 (1985) 1619 A.R Jayakrishnan, V.A Kevin, T Athul, J.P.B Silva, K Kamakshi, D Navneet, K.C Sekhar, J Agostinho Moreira, M.J.M Gomes, Composition-dependent xBa(Zr0.2Ti0.8)O3-(1-x)(Ba0.7Ca0.3)TiO3 bulk ceramics for high energy storage applications, Ceram Int 45 (2019) 5808e5818 Yuan, F Yao, Y Wang, R Ma, H Wang, Relaxor-ferroelectric 0.9BaTiO30.1Bi(Zn0.5Zr0.5)O3 ceramic capacitors with high energy density and temperature stable energy storage properties, J Mater Chem C (2017) 9552e9558 H Miura, Cellcalc: a unit cell parameter refinement program on Windows computer, J Crystallogr Soc Jpn 45 (2003) 145 M.P Rao, V.P Nandhini, J.J Wu, A Syed, F Ameen, S Anandan, Synthesis of Ndoped potassium tantalate perovskite material for environmental applications, J Solid State Chem 258 (2017) 647e655 [18] L Jin, F Li, S Zhang, Decoding the fingerprint of ferroelectric loops: comprehension of the material properties and structures, J Am Ceram Soc 97 (2014) 1e27 [19] A.R Jayakrishnan, V.A Kevin, K Kamakshi, J.P.B Silva, K.C Sekhar, M.J.M Gomes, Enhancing the dielectric relaxor behavior and energy storage properties of 0.6Ba(Zr0.2Ti0.8)O3e0.4(Ba0.7Ca0.3)TiO3 ceramics through the incorporation of paraelectric SrTiO3, J Mater Sci Mater Electron 30 (2019) 19374e19382 [20] S Nie, B Gao, X Wang, Z Cao, E Guo, T Wang, The influence of holding time on the microstructure evolution of Mge10Zne6.8Gde4Y alloy during semisolid isothermal heat treatment, Metals (2019) 420 [21] B Binesh, M Aghaie-Khafri, RUE-based semi-solid processing: microstructure evolution and effective parameters, Mater Des 95 (2016) 268e286 [22] Z Zhao, V Buscaglia, M Viviani, M.T Buscaglia, L Mitoseriu, A Testino, M Nygren, M Johnsson, P Nanni, Grain-size effects on the ferroelectric behavior of dense nanocrystalline BaTiO3 ceramics, Phys Rev B 70 (2004), 024107 [23] Y Pu, M Yao, L Zhang, P Jing, High energy storage density of 0.55Bi0.5Na0.5TiO3- 0.45Ba0.85Ca0.15Ti0.9-xZr0.1SnxO3 ceramics, J Alloys Compd 687 (2016) 689e695 [24] Y Mouteng, P Yongping, Z Lei, C Min, Enhanced energy storage properties of (1-x)Bi0.5Na0.5TiO3-xBa0.85Ca0.15Ti0.9Zr0.1O3 ceramics, Mater Lett 174 (2016) 110e113 [25] N Dan, L.V Cuong, B.D Tu, P.D Thang, L.X Dien, V.N Hung, N.D Quan, Effect of crystallization temperature on energy-storage density and efficiency of lead-free Bi0.5(Na0.8K0.2)0.5TiO3 thin films prepared by sol-gel method, J Sci.: Adv Mater Devices (2019) 370e375 [26] D Zhan, Q Xu, D Huang, H Liu, W Chen, F Zhang, Dielectric nonlinearity and electric breakdown behaviors of Ba0.95Ca0.05Zr0.3Ti0.7O3 ceramics for energy storage utilizations, J Alloy Comp 682 (2016) 594e600 [27] D Zhan, Q Xu, D Huang, H Liu, W Chen, F Zhang, Contributions of intrinsic and extrinsic polarization species to energy storage properties of Ba0.95Ca0.05Zr0.2Ti0.8O3 ceramics, J Phys Chem Solids 114 (2018) 220e227 [28] D.K Kushvaha, S.K Rout, B Tiwari, Structural, piezoelectric and high density energy storage properties of lead-free BNKT-BCZT solid solution, J Alloy Comp 782 (2019) 270e276 [29] W Ping, W Liu, S Li, Enhanced energy storage property in glass-added Ba(Zr0.2Ti0.8)O3-0.15(Ba0.7Ca0.3)TiO3 ceramics and the charge relaxation, Ceram Int 45 (2019) 11388e11394 [30] X Chen, X Chao, Z Yang, Submicron barium calcium zirconium titanate ceramic for energy storage synthesised via the co-precipitation method, Mater Res Bull 11 (2019) 259e266 Please cite this article as: A.R Jayakrishnan et al., Microstructure tailoring for enhancing the energy storage performance of 0.98[0.6Ba(Zr0.2Ti0.8) O3-0.4(Ba0.7Ca0.3)TiO3]-0.02BiZn1/2Ti1/2O3 ceramic capacitors, Journal of Science: Advanced Materials and Devices, https://doi.org/10.1016/ j.jsamd.2019.12.001 ... [0. 6Ba( Zr0. 2Ti0. 8) O3 -0. 4( Ba0. 7Ca0. 3) TiO3] -0. 02BiZn1/ 2Ti1/ 2O3 ceramic capacitors can be tuned through the modification of the sample microstructure The formation of the 0. 98 [0. 6Ba( Zr0. 2Ti0. 8) O 30 . 4( Ba0. 7Ca0. 3) TiO3] -0. 02BiZn1/ 2Ti1/ 2O3 solid... Jayakrishnan et al., Microstructure tailoring for enhancing the energy storage performance of 0. 98 [0. 6Ba( Zr0. 2Ti0. 8) O3 -0. 4( Ba0. 7Ca0. 3) TiO3] -0. 02BiZn1/ 2Ti1/ 2O3 ceramic capacitors, Journal of Science:... 1 .00 35 1 .00 43 1 .00 79 1 .00 24 1 .00 71 41 43 49 57 34 38 c n ¼( À 1)* 100 a 0. 28 0. 35 0. 43 0. 79 0. 24 0. 71 sintered for 11 h Furthermore, the reflection at 2q z 66 splits into two corresponding to the