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1.
Barium strontium titanate, (BaxSr1?x)TiO3 (BST) thin films have been prepared on alumina substrate by sol–gel technique. The X-ray patterns analysis indicated that the thin films are perovskite and polycrystalline structure. The interdigital electrode with 140 nm thickness Au/Ti was fabricated on the film with the finger length of 80 μm, width of 10 μm and gaps of 5 μm. The temperature dependence of dielectric constant of the BST thin films in the range from ?50 °C to 50 °C was measured at 1 MHz. The dielectric properties of the BST thin films were measured by HP 8510C vector network analyzer from 50 MHz to 20 GHz. 相似文献
2.
Ba0.6Sr0.4TiO3, Ce-doped Ba0.6Sr0.4TiO3, Mn-doped Ba0.6Sr0.4TiO3, (Ce,Mn) co-doped Ba0.6Sr0.4TiO3 (abbreviated as BST, BSTCe, BSTMn, BSTCeMn) thin films were deposited on LaNiO3(LNO)/Si substrates. The effects of ion doping on the microstructure and electrical properties of BST-based thin film have been researched and discussed. The X-ray diffraction pattern shows that each sample has pure perovskite phase structure with high (l00) peaks. The microstructure of each film is quite dense with uniform size. Compared with pure BST, improved insulating properties can be found in ion-doped BST thin films. For all the films, Ohmic conduction, space charge limited conduction and interface-limited Fowler-Nordheim tunneling should be the main conduction mechanisms within different electric field regions. For the case of BSTCeMn thin film, it possesses enhanced energy storage performance with a recoverable energy storage density (18.01?J/cm3) and a energy storage efficiency (75.1%) under 2000?kV/cm. This can be closely related to the small remanent polarization value (Pr=?1.89 μC/cm2), large maximum polarization value (Pmax=?28.08?μC/cm2) as well as big maximum electric field (2000?kV/cm). Also, it exhibits a large dielectric constant of 405 and a small dissipation factor of 0.075 at 500?kHz. 相似文献
3.
Zetian Yang Hongliang Du Li Jin Qingyuan Hu Shaobo Qu Zhaoning Yang Ying Yu Xiaoyong Wei Zhuo Xu 《Journal of the European Ceramic Society》2019,39(9):2899-2907
Although tremendous achievements have been made in enhancing recoverable energy storage density (Wrec) of lead-free dielectric ceramics for electrical energy storage applications in recent years, these ceramics with high Wrec still have two disadvantages: complex chemical composition and difficult preparation process. In this work, we selected NaNbO3 (NN)-based ceramics as base materials and used Bi2O3 as a sintering aid to reduce porosity and enhance dielectric breakdown strengths. Encouragingly, high Wrec, simple chemical composition and facile preparation process were simultaneously realized in 0.77NaNbO3-0.23BaTiO3 (0.77NN-0.23BT) ceramics. A large Wrec of 1.5 J cm?3 at 175 kV cm?1 and excellent thermal stability (variation of Wrec < 15% over the temperature range of 20?140 °C) were simultaneously achieved in 0.77NN-0.23BT ceramics. More importantly, this work could bring out the development of a series of NN-based ceramics for electrical energy storage in the future such as NN-ABO3 (A = Ca and Sr; B = Ti and Zr). 相似文献
4.
《Journal of the European Ceramic Society》2023,43(6):2426-2441
(1–x)Ba0.55Sr0.45TiO3–xBi(Mg0.5Ti0.5)O3 (x = 0, 0.08, 0.1, 0.12, 0.15, 0.2) ceramics were fabricated via a solid-state reaction route. The ultrahigh recoverable energy density (Wrec = 4.05 J cm?3), efficiency (η = 78%), maximum polarization (Pmax = 51.40 μC cm?2), and high dielectric breakdown strength (BDS = 230 kV cm?1) were achieved for the 0.9BST?0.1BMT ceramic. The fast discharge rate (t0.9~0.14 μs), current density (CD~637.02 A cm?2), high power density (PD~38.70 MW cm?3), good temperature stability (20?180 °C), frequency stability (10?500 Hz), and fatigue endurance for cycling (105) of 0.9BST?0.1BMT ceramic make it suitable for the development of energy-storage devices. The relaxor behavior with a high Wrec (3.06 J cm?3) and η (93%) at BDS (220 kV cm?1) was also achieved for the 0.8BST?0.2BMT ceramic. This study systematically investigates the correlation among the structural, dielectric, impedance, and energy storage properties of BMT-doped BST ceramics. 相似文献
5.
《Ceramics International》2023,49(5):7905-7912
Because of their possible applications in dielectric energy-storage capacitor devices, (Bi0.5Na0.5)TiO3-based (BNT) relaxor ferroelectric (RFE) ceramics are feasible alternatives to lead-containing electroceramics. Good energy-storage performance (ESP), including high recoverable energy density (Wrec) and good energy discharge efficiency (η), is required to achieve device miniaturization and long device lifetimes. An advanced method was used to overcome the challenges of A-site ionic disordered RFE in achieving high inducible polarization and low hysteresis, with the former dictating a large Wrec and the latter dictating a high η. In this study, an ABO3 perovskite-structured complex end-member Bi(Mg2/3Nb1/3)O3 (BMN) was added to a 0.7Bi0.5Na0.4K0.1TiO3–0.3Ba0.5Sr0.5TiO3 (0.7BNKT–0.3BST) matrix. The differences in the valence states and ionic radii of Mg2+, Ti4+, and Nb5+ increased the local electric field fluctuation, which contributed to the expanded dielectric relaxation properties. The combined substantial prevention of hysteresis and remanent polarization suggests high potential applicability for ESP. Finally, an enhancement in Wrec to 4.98 J/cm3 was achieved in 0.595BNKT–0.255BST–0.15BMN with an ultrahigh η of 97.3% in a medium-strength electric field of 300 kV/cm. The ESP also demonstrated good thermostability between 30 and 120 °C. Furthermore, the strategy used in this study to generate RFEs can serve as a guide for future research. 相似文献
6.
《Ceramics International》2022,48(14):19864-19873
Dielectric energy storage materials with congenitally high power densities and ultrafast discharge rates have been extensively studied for emergent applications. As a typical and traditional dielectric material, paraelectric Ba0.4Sr0.6TiO3 (BST) ceramic exhibits a moderate dielectric constant (εr), low dielectric loss and slightly nonlinear P–E hysteresis. However, its energy storage density (W) is extremely low because of its low maximum polarisation (Pmax) and weak breakdown strength (BDS). In this study, ferroelectric Na0.5Bi0.5TiO3 (NBT) was introduced into paraelectric BST to enhance energy storage performance. The results show that the introduction of NBT induced polar nano-regions (PNRs) in the paraelectric matrix, resulting in a slim hysteresis loop with low remnant polarisation (Pr) and high Pmax simultaneously. Furthermore, owing to a decrease in the oxygen vacancy concentration and an increase in the band gap energy, the BDS of the BST ceramic also significantly increased. As a consequence, a remarkable energy storage density (Wrec = 3.89 J/cm3) and a high energy storage efficiency (η = 83.8%) were realised in the 0.75Ba0.4Sr0.6TiO3-0.25Bi0.5Na0.5TiO3 (0.75BST–0.25NBT) ceramic under a practical electric field of 360 kV/cm. Moreover, the ceramic also exhibited an excellent current density (~1029.7 A/cm2) and ultrahigh power density (~128.7 MW/cm2). The attained energy storage performances indicate that the NBT-modified BST ceramics are promising materials for high energy storage capacitor applications field. 相似文献
7.
《Ceramics International》2019,45(11):13772-13779
The lead-free KNN (K0.5Na0.5NbO3) films were co-doped with Mn-Ta and Mn-Ti via the Sol-Gel method. With Mn doping, the leakage behavior in the KNN films is significantly weakened. Annealed at 700 °C, the KNNM film shows good crystallinity, dense morphology and better energy storage performance. With Mn-Ta and Mn-Ti co-doping, the KNNM4R (K0.5Na0.5Nb0.96-xMn0.04RxO3, R = Ta, Ti) films still show tetragonal phase and the smoothest surface morphology at 6mol% Ta or Ti content, with about 200 nm in thickness. Under the breakdown field strength of 2700 kV/cm and 2800 kV/cm, the (Pm-Pr) of Ta6 and Ti6 films are 20.7 μC/cm2 and 22.4 μC/cm2, the Wrec and η are up to 20.7 J/cm3, 23.9 J/cm3 and 57%, respectively. 相似文献
8.
《Ceramics International》2022,48(15):21407-21415
This work presents a simple process to fabricate Na0.5Bi0.5(Ti0.97Fe0.03)O3/Ba(1–x)SrxTiO3–based heterostructure thin films with a compositional graded sequence, and their energy storage properties are investigated systematically. A simulation technique is used to predict the experimental results. Interestingly, improved energy storage properties are obtained in the “up–graded” film, which is associated with the stress/strain. Furthermore, the “up–graded” film after aging with treating exhibits a higher breakdown strength (EBD = 3176.4 kV/cm), recoverable energy storage density (Wrec = 67.18 J/cm3) and efficiency (η = 75.65%). This can be attributed to the ordered defect dipoles induced by aging with treating driving domain switching, which is favorable for high (Pm–Pr) and large Wrec. These results provide an approach and guidance to design thin film-based devices with optimal energy storage performance. 相似文献
9.
《Journal of the European Ceramic Society》2023,43(4):1523-1530
Developed ceramic capacitors with excellent recoverable energy storage density (Wrec) and efficiency (η) are greatly desired for next-generation pulsed power devices but challenge as well. Herein, outstanding Wrec of 5.2 J/cm3 and η of 82% are achieved in the PbO-doped fine grain Bi0.25Na0.25Sr0.5TiO3 (BNST-P) based relaxor ferroelectric ceramics. The corresponding mechanism is that A-site Pb-doping increases maximum polarization and breakdown strength, and suppresses remnant polarization simultaneously. Meanwhile, the energy storage property possesses excellent temperature and frequency stability, and the variation of Wrec and η is less than 5% within the range of 25–100 °C and 2–100 Hz. Encouragingly, superior charge-discharge performance with fast discharge speed t0.9 of 24 ns and high power density PD of 296 MW/cm3 is obtained. These striking comprehensive results suggest BNST-P ceramics possess potential prospects for applications. 相似文献
10.
《Journal of the European Ceramic Society》2006,26(10-11):1873-1877
We fabricated (Ba0.6Sr0.4)TiO3 (BST) thin films of various thicknesses on sapphire (−1 1 2 0) substrates using metal-organic decomposition method. These films showed grain growth from 160 to 650 nm with an increase in the thickness from 90 to 1050 nm. At microwave frequencies, the measured capacitances of the planar capacitors decreased with the film thickness because the electro-magnetic field propagates across high permittivity BST films to the low permittivity sapphire substrate. However, we found that the BST-thin film permittivity remained large up to 90 nm thick, based on electro-magnetic field analysis using the finite element method. On the other hand, the BST thin film tunability decreased with the film thickness. 相似文献
11.
《Ceramics International》2022,48(5):6062-6068
As microelectronic devices move toward integration and miniaturization, the thin film capacitors with high energy density and charge/discharge efficiency have attracted immense interests in modern electrical energy storage systems. Despite morphotropic phase boundary (Na0.8K0.2)0.5Bi0.5TiO3-based lead-free materials with outstanding ferroelectric and piezoelectric properties, while large ferroelectric hysteresis with high remanent polarization (Pr) hinder to improve energy storage capability. Here, novel lead-free relaxor-ferroelectric (RFE) thin film capacitors with high energy density are successfully prepared in (1-x) (Na0.8K0.2)0.5Bi0.5TiO3-xBa0.3Sr0.7TiO3 [(1-x)NKBT-xBST] systems. Introducing BST into the NKBT systems is expected to reduce remanent polarization (Pr) on account of coupling reestablishment of the polar nano-regions (PNRs) and improving the relaxation behavior. As a result, 0.6NKBT-0.4BST thin film exhibits high energy density (Wrec ~ 54.79 J/cm3) together with satisfactory efficiency (η ~ 76.42%) at 3846 kV/cm. The stable energy storage performances are achieved within the scope of operating temperatures (20–200 °C) and fatigue cycles (1-107 cycles). This work furnishes a new technological way for the design of high energy-density thin film capacitors. 相似文献
12.
《Journal of the European Ceramic Society》2022,42(11):4528-4538
Ideal relaxor antiferroelectrics (RAFEs) have high field-induced polarization, low remnant polarization and very slim hysteresis, which can generate high recoverable energy storage Wrec and high energy storage efficiency η, thus attracting much attention for energy storage applications. True RAFEs, on the other hand, are extremely rare, and the majority of them contain environmentally hazardous lead. In this work, we use a viscous polymer rolling process to synthesize a novel and eco-friendly 0.65Bi0.5Na0.4K0.1TiO3-0.35[2/3SrTiO3-1/3Bi(Mg2/3Nb1/3)O3] (BNKT-ST-BMN) dielectric material, which possesses a very typical RAFE-like characteristic. As a result, this material has a high Wrec of 4.43 J/cm3 and a η of 86% at an electric felid of 290 kV/cm, as well as a high thermal stability of Wrec (>3 J/cm3) over a wide range of 30–140 °C at 250 kV/cm. Our findings suggest that the BNKT-ST-BMN material could be a potential candidate for use in energy storage pulse capacitors. 相似文献
13.
The BaSn0.15Ti0.85O3 (BTS) thin films are prepared on Pt-Si substrates with thickness ranging from ~ 60?nm to ~ 380?nm by radio frequency magnetron sputtering. The effects of thickness on microstructure, surface morphologies and dielectric properties of thin films are investigated. The thickness dependence of dielectric constant is explained based on the series capacitor model that the BTS thin film is consisted by a BTS bulk layer and an interfacial layer (dead layer) between the BTS and bottom electrode. The thin films with thickness of 260?nm give the largest figure of merit of 76.9@100?kHz, while the tunability and leakage current density are 64.6% and 7.46?×?10?7 A/cm2 at 400?kV/cm, respectively. 相似文献
14.
Shuanghao Wu Pan Chen Jiwei Zhai Bo Shen Peng Li Feng Li 《Ceramics International》2018,44(17):21289-21294
Fe-doping is an effective way to improve physical performances of piezoelectric and ferroelectric materials. Under such circumstances, x mol% (x?=?0.0, 1.0, 1.5, 2.5) Fe-doped 0.72Bi0.5Na0.5TiO3–0.18Bi0.5K0.5TiO3–0.10SrTiO3 (BNT–BKT–ST–xFe) thin films were prepared by sol-gel method and the relationships between the content of Fe and electromechanical properties of the films were studied. The BNT–BKT–ST–1.0Fe thin films exhibit the best electromechanical properties, whose Smax/Emax, Wrec, η, Pmax, Prem and εr of are 68.00?pm/V, 20.34?J/cm3, 65.17%, 71.5?μC/cm2, 14.8?μC/cm2, 868 respectively. These results indicate that BNT–BKT–ST–1.0Fe thin films are promising for applications for advanced piezoelectric materials and capacitors with high energy-storage density. 相似文献
15.
《Journal of the European Ceramic Society》2020,40(15):5450-5457
BiFeO3-BaTiO3-based relaxor ferroelectric ceramic has attracted increasing attention for energy storage applications. However, simultaneously achieving high recoverable energy storage density (Wrec) and efficiency (η) under low electric field has been a longstanding drawback for their practical applications. Herein, a novel relaxor ferroelectric material was designed by introducing (Sr0.7Bi0.2)TiO3 (SBT) into the composition 0.67BiFeO3-0.33BaTiO3 (BF-BT-xSBT). A large Wrec of ∼2.40 J/cm3 and a high η of ∼90.4 % were simultaneously realized under a low electric field of 180 kV/cm, which is superior to that of most previously reported lead-free ceramics. Moreover, moderate temperature endurance and excellent frequency stability were also obtained. More importantly, this ceramic has a large discharge current density (∼289.18 A/cm2), a discharge power density (∼14.46 MW/cm3) and short discharge time (<0.25 μs). These results not only demonstrate superior potential in BF-BT-SBT ceramics, but also offer a new design to tune the energy storage performance of lead-free relaxor ferroelectric ceramics. 相似文献
16.
Lirong Song Ying Chen Genshui Wang Lihui Yang Jun Ge Xianlin Dong Pinghua Xiang Yuanyuan Zhang Xiaodong Tang 《Journal of the American Ceramic Society》2014,97(10):3048-3051
Ba0.63Sr0.37TiO3 (BST) films were first deposited on SiC substrates with LNO bottom electrodes by magnetron sputtering. The BST/LNO/SiC thin films exhibit high dielectric tunability and low dielectric loss while maintaining excellent temperature coefficient of dielectric constant in the temperature range between 250 and 350 K. We also investigated the effect of film thickness on the dielectric properties. BST(430 nm)/LNO/SiC film has higher tunability (68.09% @700 kV/cm), lower loss tangent (tanδ = 0.00987) and quite a bit higher figure of merit (FOM = 68.99) as compared with that of BST(300 nm)/LNO/SiC film. Our results demonstrate that combining ferroelectric BST films with SiC substrates is very promising for the development of tunable devices over a large temperature range. 相似文献
17.
A.Z. Simões C.R. Foschini F. Moura J.A. Varela E. Longo 《Ceramics International》2012,38(5):3841-3849
Bi0.85La0.15FeO3 (BLFO015) thin films were deposited by the polymeric precursor solution on La0.5Sr0.5CoO3 substrates. For comparison, the films were also deposited on Pt bottom electrode. X-ray diffraction data confirmed the substitutions of La into the Bi site with the elimination of all secondary phases under a substitution ratio x = 15% at a temperature of 500 °C for 2 h. A substantial increase in the remnant polarization (Pr) with La0.5Sr0.5CoO3 bottom electrode (Pr ≈ 34 μC/cm2) after a drive voltage of 9 V was observed when compared with the same film deposited on Pt substrate. The leakage current behavior at room temperature decreased from 10?8 (Pt) to 10?10 A/cm2 on (La0.5Sr0.5CoO3) electrode under a voltage of 5 V. The fatigue resistance of the Au/BLFO015/LSCO/Pt/TiO2/SiO2/Si (1 0 0) capacitors with a thickness of 280 nm exhibited no degradation after 1 × 108 switching cycles at a frequency of 1 MHz. 相似文献
18.
Xing-Hua Fu Ling-Jun Yu Yong-Tao Cui Li-Qiang Xin 《Journal of Inorganic and Organometallic Polymers and Materials》2012,22(1):54-58
Using the sol–gel method, La1−x
Sr
x
CoO3 (LSCO) electrode films were first fabricated on the Si (100) substrates, followed by the growth of Ba1−x
Sr
x
TiO3 (BST) thin films on the LSCO electrode film. The crystal structure and surface morphology of these films were characterized
by XRD and SEM. The effects of Sr-doping and annealing temperature on the structure and electric resistivity of the LSCO films
and the dielectric properties of the BST films were studied. Results show that the La0.5Sr0.5CoO3 electrode annealed at 750 °C has the lowest electric resistivity, 1.1 × 10−3Ω cm. The relative permittivity of the La0.5Sr0.5CoO3-supported BST films first increases and then decreases with Sr-doping. The relative permittivity of the BST film decreases
while the dielectric loss increases with frequency. Among the studied BST films, Ba0.5Sr0.5TiO3 has the largest relative permittivity and the smallest dielectric loss (95 and 0.1, respectively) when the frequency is 1 kHz. 相似文献
19.
Ultraviolet pulsed laser crystallization of Ba0.8Sr0.2TiO3 films on LaNiO3-coated silicon substrates
《Ceramics International》2016,42(3):4039-4047
In this work, Ba0.8Sr0.2TiO3 (BST) films on LaNiO3-buffered SiO2/Si (LNO/SiO2/Si) substrates were crystallized by pulsed laser irradiation. Solution-derived amorphous barium–strontium–titanate precursor layers were crystallized with a KrF excimer laser in oxygen ambient at fluences ranging from 50 to 75 mJ cm−2. With the substrate temperature set to 500 °C, the number of pulses and film thickness were varied until high-quality crystallinity could be achieved. It was found that films with a thickness of 40 nm are fully crystallized with a uniaxial {00l} orientation which is predetermined by the LaNiO3 orientation. On the other hand, for 160 nm thick films, crystallization was observed after 12,000 pulses in the 70 nm close to the surface, while the rest of the film remained amorphous. The large temperature difference between the film surface and interface due to the low thermal conductivity of the amorphous BST is suggested as the origin of this behavior. Films thicker than 80 nm cracked on crystallization due to the stress caused by the different thermal expansion coefficients of film and substrate, as well as the large temperature variations within the BST film. 相似文献
20.
《Ceramics International》2022,48(22):33553-33562
In this investigation, La2O3 was doped into 0.85(0.65BF-0.35BT)-0.15Sr0.7Bi0.2TiO3 (BF-BT-SBT) to form a solid solution with relaxation ferroelectric properties. The dielectric breakdown strength (BDS) of 1% mole of La doping was 220 kV/cm, the maximum recoverable energy storage (Wrec) was 2.35 J/cm3, and the energy storage efficiency (η) was 71%. The relationship between ceramic properties and microstructure was investigated in detail. Doping with La has the following main features: (1) The dissolution of La3+ ions in the A position of the original perovskite structure reduced the concentration of oxygen vacancies in the lattice and played a role of compensating the defects. (2) The dielectric loss of ceramics was reduced, the impedance was greatly increased, and the specimen exhibited a high-temperature stability: a maximum Wrec of 4.04 ± 1.7% J/cm3 in 30–130 °C. (3) The core–shell–like with single phase structure in La-doped ceramics had been successfully observed, which may become a strategy for preparing high-performance ceramics. Higher BDS and denser structures were obtained in 0.01 La ceramics by further optimizing the preparation of the above compositions by the viscous polymer process (VPP). The BDS of 0.01La ceramics prepared by VPP reached 480 kV/cm, the effective energy storage density reached 6.15 J/cm3, and the η was about 81%. This made La-doped 15SBT (chemical composition of BF-BT-SBT + La2O3) ceramics become a potential candidate material for energy storage devices. 相似文献