CERES :: Browsing by Author "Zhang, Qi"

Browsing by Author "Zhang, Qi"

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Open Access
2D ultrathin carbon nanosheets derived from interconnected Al-MOF as excellent hosts to anchor selenium for Li-Se battery
(Elsevier, 2019-05-29) Jin, Wen-Wu; Li, He-Jun; Zou, Ji-Zhao; Inguva, Saikumar; Zhang, Qi; Zeng, Shao-Zhong; Xu, Guo-Zhong; Zeng, Xie-Rong
Alleviating volume expansion of the electrodes and improving utilization of the active materials have become key problems restricting a successful commercialization of lithium-selenium batteries. In this paper, a 2D ultrathin carbon nanosheets derived from interconnected MOF is designed for the first time. Such carbon nanosheets are composed by parallel stacked 2D sub-units, and this unique hierarchical porous architecture is beneficial for buffering the volume expansion and for improving the utilization rate of the active materials. Therefore, the cathode displays an excellent cycling stability with a reversible capacity of 347.3 mAh g−1 at 2 C after 240 cycles.
Open Access
Adhesiveless bonding of wood - a review with a focus on wood welding
(North Carolina State University, 2021-08-01) Gedara, Ajith K.A.; Chianella, Iva; Endrino, José L.; Zhang, Qi
Most industrially used synthetic wood adhesives release formaldehyde, which is carcinogenic for humans. Adhesiveless bonding of wood can be achieved using heat treatment by either hot-pressing method, suitable mainly for wood particles and fibres or by wood welding. Welding of wood, which relies on the heat generated via friction, can be used for bonding two or more solid wood pieces together. The process can be carried out either by linear or rotational wood welding. This review first considers the manufacturing of binderless wood-based panels by hot-pressing. Then this is followed by an in-depth outlook of wood welding and its application in the wood industry. The effects of varying wood welding parameters, such as applied pressure, vibrational frequency and amplitude, holding pressure, holding time, welding time in linear wood welding, and relative diameter difference between the substrate and the dowel in rotational wood welding to obtain joints with optimal mechanical and physical properties is reviewed and discussed. Wood products made by heat treatment (hot-pressing and wood welding) are environmentally friendly, and the brief curing times needed for their manufacture represent a great advantage compared with the usage of wood adhesives to bind pieces of wood.
Open Access
Al-based MOF derived self-assembled carbon nanosheets as innovative anodes for Li-and Na-ion batteries
(IOP, 2019-12-20) Zeng, Xie-Rong; Wenwu, Jin; Li, Hejun; Saikumar, Inguva; Zhang, Qi; Shaozhong, Zeng; Guozhong, Xu; Zou, Jizhao
Functional modification and structural design of carbon electrode materials are considered as a cost-effective method to improve their electrochemical performance. In this study, a solvothermal method is applied to realize self-assembly of the metal-organic framework. After simple carbonization and acid treatment, carbon nanosheets with 2D adjustable defective sub-units are successfully prepared for the first time. It is found that carbonization temperature has a significant effect on the carbon skeleton structure. The optimal nanostructures with large specific surface area and appropriate pore size distribution make self-assembled carbon nanosheets having excellent Li/Na- ion storage properties. In addition, the adjustable carbon skeleton structure can effectively avoid irreversible damage when charge-discharge cycles. For Li-ion batteries, a specific capacity of 825 mAh g−1 is achieved after 100 cycles at 0.1 C, while for Na-ion batteries a specific capacity of 193 mAh g−1 is observed after 100 cycles at 0.5 C. Moreover, for Na-ion batteries, even at a high rate of 5 C the material delivers a specific capacity of 109.5 mAh g−1 after 3500 cycles.
Open Access
Alleviate the J - V hysteresis of carbon-based perovskite solar cells via introducing additional methylammonium chloride into MAPbI3 precursor
(Royal Society of Chemistry, 2018-10-15) Jiang, Huirong; Liu, Xingyu; Chai, Nianyao; Huang, Fuzhi; Peng, Yong; Zhong, Jie; Zhang, Qi; Ku, Zhiliang; Chenga, Yi-bing
The hysteretic phenomenon commonly exists in the J–V curves of perovskite solar cells with different structures, especially for carbon-based mesoscopic perovskite solar cells without hole-conductor (carbon-based PSCs). By adding moderate amounts of methylammonium chloride (MACl) into MAPbI3 perovskite precursor, we found the J–V hysteresis of carbon-based PSCs could be significantly alleviated and the crystallinity of MAPbI3 perovskite could also be influenced. With the increasing amount of MACl, MAPbI3 perovskite showed better and better crystallinity until the MACl came to 0.45 M. The champion device with 0.45 M of additional MACl exhibited a preferable PCE of 14.27% for reverse-scan (RS) and 14.50% for forward-scan (FS), significantly higher than that of the pristine device (8.74% for RS and 4.80% for FS). What's more, the J–V hysteretic index of the device gradually decreased along with the increasing amount of MACl, and kept at low value even when the crystallinity of MAPbI3 perovskite became poor. Through XRD and PL analysis, we demonstrated that the recombination rate of the accumulated charges at the perovskite/TiO2 interface is the main reason for photocurrent hysteresis in carbon-based PSCs. High quality of perovskite crystals is an important contributing factor for high-performance PSCs with low hysteresis, but there is no necessary correlation between low hysteresis and good crystallinity. This research presents an effective way to fabricate carbon-based PSCs with low-hysteresis, and at the same time, provides evidence for investigating the origin of J–V hysteresis of PSCs.
Open Access
Asymmetry of domain forward switching and multilevel relaxation times of domain backswitching in antiferroelectric Pb0.99Nb0.02(Zr0.84Sn0.12Ti0.04)0.98O3 thin films
(American Institute of Physics, 2007-04) Jiang, A. Q.; Lin, Y. Y.; Tang, T. A.; Zhang, Qi
Pb0.99Nb0.02(Zr0.84Sn0.12Ti0.04)0.98O3 thin films demonstrate a double hysteresis loop characteristic of antiferroelectric behavior with film thickness at above 150 nm, but only one branch of the loop is present in films that are 90 nm thick. The relaxation time of domain backswitching from ferroelectric into antiferroelectric is multistaged in a range of 100 ns–100 ms, but it is less than 100 ns in the films without Sn and Nb dopants. Electrical modeling of the films composed of elementary regions with inhomogeneities of dielectric constant, conductivity, and polarization embodies the essence of charge injection for the compensation of local backswitching field of domains.
Open Access
Bismuth ferrite materials for solar cells: Current status and prospects
(Elsevier, 2018-10-09) Chen, Guang; Chen, Jian; Pei, Weijie; Lu, Yinmei; Zhang, Qingfeng; Zhang, Qi; He, Yunbin
Different from classical semiconductor photovoltaic devices, for ferroelectric photovoltaic devices, the open-circuit voltage (Voc) can be four and even more orders of magnitude larger than the band gap of the ferroelectric, and the built-in electric field arising from the remnant polarization of the ferroelectric is throughout the bulk region, which is good for obtaining giant power conversion efficiency. Among ferroelectric materials, BiFeO3 with remnant polarization of as high as ∼100 μC/cm2 has the narrowest direct band gap (∼2.7 eV). These indicate that high power conversion efficiency may be obtained in BiFeO3-based photovoltaic devices. Also, some significant research results about photovoltaic effects of BiFeO3 materials have been recently acquired. In order to better promote the development of BiFeO3-based photovoltaic devices, in this paper, we present a comprehensive review on the latest research progress in photovoltaic effects of BiFeO3 materials with different kinds of topography, including bulk, thin film, and nanomaterials.
Open Access
Ca(Mg1/3Ta2/3)O3 dielectric thin films: preparation, structure, mechanical and dielectric properties
(Springer, 2016-05-17) Li, Runrun; Zhou, Jing; Chen, Wen; Zhang, Qi; Bao, Yiwang Bao
The effects of annealing temperature on the crystallinity, grain size and hence mechanical and dielectric properties of Ca(Mg1/3Ta2/3)O3 (CMT) dielectric films were systematically studied. The CMT thin films were fabricated by an aqueous solution-gel technology and exhibited uniform, smooth and dense morphologies. The optimum pyrolysis temperature and time was 550 °C and 330 s, respectively. All the CMT films annealed from 650 to 800 °C show a single perovskite phase and the crystallization increases with increasing the annealed temperature but a secondary phase is observed in the film annealed at 900 °C. The hardness and reduced modulus were effectively enhanced by increasing the annealing temperature, which can be correlated to the crystallinity and densification improvements. Higher elastic recovery was observed for CMT films annealed at higher temperatures indicating less difficult recoveries for those films. We also noticed that the dielectric constants were improved for the samples annealed at higher temperature, which may enable higher performances for future microwave communication electronics.
Open Access
Carbon-coated fluorinated graphite for high energy and high power densities primary lithium batteries
(Elsevier Science B.V., Amsterdam., 2010-05-01T00:00:00Z) Zhang, Qi; D'Astorg, S.; Xiao, P.; Zhang, X.; Lu, L.
The electrochemical performances of fluorinated graphite have been improved by coating a uniform carbon layer on commercial CFx (x = 1) powder used as cathode material in lithium battery. In comparison with the cell using un-coated CFx as cathode, the cell using carbon coated CFx cathode has a higher energy density and higher power density, particularly at higher discharge current rates (1C above). This is because the conductive carbon coating provides the exterior connectivity between particles for facile electron conduciton, resulting in high rate performance.
Open Access
Characterisation of lead barium zirconate thin films for utilisation of the electrocaloric effect
(Elsevier, 2016-05-09) Shaw, Christopher P.; Zhang, Qi; Correia, T. M.; Weaver, P. M.
Characterisation of a composition of Lead Barium Zirconate thin films deposited by a spin coating sol-gel process onto platinised silicon substrates has been undertaken to investigate a potential application utilising the reported electrocaloric properties of the material. Xray diffraction studies revealed that above 700 °C the presence of pyrochlore phase was replaced by ferroelectric phase but the identification of antiferroelectric phases previously reported could not be identified. Wet etching of the films produced an insoluble residue containing only evidence of zirconium out of the original three metals, which resembled a skeletal structure similar to the original rosette morphology of the annealed films. Elemental analysis of the annealed films using EDX indicated a non-target Pb:Ba:Zr ratio, which suggested a reduced Zr content of the films. “Solution-like” rather than “sol-like” nature of the spin coated sol and phase boundary proximity are proposed for reported observations, and a mechanism is proposed to account for the unusual observed trend in dielectric constant.
Open Access
Chemical synthesis of nanoparticles and electrohydrodynamic manipulation of nanoparticulate suspensions
(Cranfield University, 2009-09) Libor, Zsuzsanna; Wilson, Stephen A.; Zhang, Qi
This research concerns the study of nanoparticle synthesis methods and the influence that nanoparticles can have on the physical and electrical properties of non-polar fluids. In this study it is demonstrated that a very small volume fraction of nanoparticles can have a very large effect on the macroscopic properties of fluids. Characterization of nanoparticles and nanofluids has led to the creation of new techniques for controlled deployment of nanoparticles within larger structures. A new dielectrophoretic technique can be used for (1) uniformly sized droplet generation and manipulation with controllable droplet size, (2) oil-in-water emulsion creation in unique way, (3) recycling nanoparticles from nanoparticulate suspensions and (4) creation of core-shell structures. Different types, sizes and morphologies of nanoparticles have been made successfully by chemical synthesis and new synthesis routes have been created. A new wet chemical route has been devised to synthesise nickel nanoparticles with controllable size and different morphology including new shapes such as micro-flower and nano-stars. PZT nanoparticles have been synthesized hydrothermally with controllable size and new morphologies created such as nearly spherical nanoparticles and pellets. A novel wet chemical synthesis method was developed to produce core-shell structures of Ni- and also Fe3O4 - coated SiO2, BT, and PZT particles. The characterization of non-polar fluid-based nanofluids included a sedimentation study, studies of the fluidic properties (viscosity and surface tension) and electrical properties such as DC conductivity and dielectric permittivity. The results clearly show that the macroscopic properties of base fluids (silicone oil and perfluorinated oil) were changed even with a very low concentration (< 0.6 vol %) of nanoparticles added. The properties of nanofluids are found to depend on the properties of the base fluid and also on the properties of the dispersed nanoparticles. Importantly, the properties are demonstrated to depend on the fluid-particle interaction.
Open Access
Coatings for the prevention of marine fouling
(Cranfield University, 2016-10) Odolczyk, Katarzyna; Zhang, Qi
Microorganisms attachment to the surfaces located in the marine water has become a significant problem. Historically, the antifouling properties of the coatings were achieved by using biocides, which had a negative consequence to the marine environment. Currently, alternative environmental friendly methods are required. This thesis aimed to investigate and produce the antifouling coatings that can be used as potential candidates in the marine industry. In this study, a range of novel polymer nanocomposite coatings was fabricated via the method of solvent and tested based on the strategy of microbial adhesion. The composition of the coatings mainly contains polidimethylsiloxane (PDMS) and different nanomaterials. The coatings applied on glass substrate were characterised using X-ray spectroscopy (XRD), scanning electron microscopy (SEM), contact angle measurements, inductively coupled plasma mass spectroscopy (ICP-MS) and atomic force microscopy (AFM). In biofouling assays, attachment of bacteria B. Subtilis and three marine microalgae (Skeletonema sp., Amphora sp., D. Salina) was investigated in laboratory scale. The obtained results suggested that small amount of nanoparticles in the polymer matrix can improve the antifouling settlement behaviour of the coatings. All microalgae attached more on PDMS/SiO2 and control surfaces (glass and PDMS) compared to the coatings containing multiwall carbon nanotubes (MWCNT) and sodium bismuth titanate (NBT). The influence of contact time, surface roughness and surface wettability was also studied. The microbial attachment varied significantly with respect to contact time and surface properties. There was no obvious evidence showing that the wetting properties and the roughness of the coatings have an effect on growth ... [cont.].
Open Access
Cobalt doped JUC-160 derived functional carbon superstructures with synergetic catalyst effect for Li-SeS2 batteries
(Elsevier, 2020-07-03) Jin, Wen-Wu; Li, He-Jun; Zou, Ji-Zhao; Zhang, Qi; Inguva, Saikumar; Zeng, Shao-Zhong; Xu, Guo-Zhong; Zeng, Xie-Rong
The carbon nanostructures with polar metal/heteroatom co-doping are considered as an effective strategy to improve their electrochemical performances. In this context, the crystal-shape engineering is carried out. Based on a new ‘‘one for six’’ strategy, the JUC-160 having a two-dimensional (2D) zeolitic imidazolate framework is transformed into six different carbon materials. These materials do not need a carbon activation process or template removal process. Instead, after a simple carbonization, a series of metal/heteroatom co-doped carbon materials with novel structures are formed. To be highlighted, this work is the first report of using self-assembled carbon nanostructures/SeS2 composites as cathode materials in the field of Li-SeS2. Moreover, those carbon nanostructures can be effectively tailored by adjusting the method of cobalt doping and the amount of cobalt dopant. Because of the benefits from the novel structures and cobalt/nitrogen co-doping, the dissolution of poly-sulfides/selenides is reduced and a high content of SeS2 (73 wt%) is achieved. The optimized cathode displays an extraordinary cycle performance with a reversible capacity of 820.87 mA h g−1 after 100 cycles, and with reversible charge-discharge efficiency is close to 100%
Open Access
Compaction of lead zirconate titanate sol-gel coatings.
(Elsevier Science B.V., Amsterdam., 2006-06-01T00:00:00Z) Khan, Mikael A.; Kurchania, Rajnish; Corkovic, Silvana; Zhang, Qi; Milne, Steven J.
A novel method for the densification of sol-gel films is presented. After elimination of organic decomposition products by heat-treatment at 350 °C and 450 °C, the films are isopressed prior to crystallisation at 550 °C. Consequently, porous lead zirconate titanate films, ~0.7 m in thickness with pore sizes of ~0.1 m could be transformed into dense 0.2 m fil
Open Access
Comparative studies of PST thin films as prepared by Sol-Gel, LDCVD and sputtering techniques
(Taylor and Francis, 2002) Huang, Zhaorong; Donohue, P. P.; Zhang, Qi; Williams, D.; Anthony, C. J.; Todd, M. A.; Whatmore, Roger W.
Lead scandium tantalate (PST) thin films for pyroelectric applications have been deposited by using liquid delivery chemical vaporise deposition (LDCVD), sputtering and sol-gel techniques. These films were annealed by using rapid thermal annealing to improve their electrical properties. Their microstructures and electrical properties such as permittivity εr, dielectric loss tanδ, pyroelectric coefficient p, and thermal detection figure of merit Fd were studied. It is suggested to use a combination of methods to depositing films and then use rapid thermal annealing to produce high quality PST thin films.
Open Access
Construction of porous hierarchical NiCo2S4 toward high rate performance supercapacitor
(Springer, 2019-11-11) Zhao, Fenglin; Huang, Wanxia; Sial, Muhammad Aurang Z. G.; Xie, Dong; Wu, Hongliang; Zhang, Qi; Zou, Jizhao; Zeng, Xierong
Developing high-performance supercapacitors is an effective way to satisfy the ever-increasing energy storage demand for emerging devices, but the inferior rate performance of battery-type supercapacitors limits their large-scale utilization. Herein, porous hierarchical nickel cobalt sulfide (NiCo2S4) was constructed by a novel strategy that the synthesized nickel cobalt oxide nanosheets as chemical template for hydrothermal method. Furthermore, the backbone of nickel cobalt oxide nanosheets can finally convert to NiCo2S4, which both plays the role of matrix to buffer the volume variation and enhances entire conductivity. Benefiting from high specific area (79.9 m2 g−1), suitable nanopores for KOH electrolyte, high conductivity, and multiple Co/Ni valence, the hierarchical NiCo2S4 electrode delivers a high specific capacity of 1035.1 F g−1 at the current density of 1 A g−1, and an ultrahigh rate performance of 80.9% capacitance retention at 20 A g−1 was obtained. The assembled asymmetric supercapacitor device could achieve the maximum capacity of 102.4 F g−1 at 5 mV s−1 and maintain at 80.5 F g−1 at 50 mV s−1, indicating its superior rate ability. In addition, the highest energy density of 35.4 Wh kg−1 can be obtained at a power density of 0.4 kW kg−1. These results indicate that the porous hierarchical NiCo2S4 could be served as high rate performance electrode materials for advanced supercapacitors.
Open Access
Controlling homogenous spherulitic crystallization for high-efficiency planar perovskite solar cells fabricated under ambient high-humidity conditions
(Wiley-VCH Verlag, 2019-10-25) Angmo, Dechan; Peng, Xiaojin; Seeber, Aaron; Zuo, Chuantian; Gao, Mei; Hou, Qicheng; Yuan, Jian; Zhang, Qi; Cheng, Yi‐Bing; Vak, Doojin
The influence of precursor solution properties, fabrication environment, and antisolvent properties on the microstructural evolution of perovskite films is reported. First, the impact of fabrication environment on the morphology of methyl ammonium lead iodide (MAPbI3) perovskite films with various Lewis‐base additives is reported. Second, the influence of antisolvent properties on perovskite film microstructure is investigated using antisolvents ranging from nonpolar heptane to highly polar water. This study shows an ambient environment that accelerates crystal growth at the expense of nucleation and introduces anisotropies in crystal morphology. The use of antisolvents enhances nucleation but also influences ambient moisture interaction with the precursor solution, resulting in different crystal morphology (shape, size, dispersity) in different antisolvents. Crystal morphology, in turn, dictates film quality. A homogenous spherulitic crystallization results in pinhole‐free films with similar microstructure irrespective of processing environment. This study further demonstrates propyl acetate, an environmentally benign antisolvent, which can induce spherulitic crystallization under ambient environment (52% relative humidity, 25 °C). With this, planar perovskite solar cells with ≈17.78% stabilized power conversion efficiency are achieved. Finally, a simple precipitation test and in situ crystallization imaging under an optical microscope that can enable a facile a priori screening of antisolvents is shown.
Open Access
CoSe2/Co nanoheteroparticles embedded in Co, Nco-doped carbon nanopolyhedra/nanotubes as anefficient oxygen bifunctional electrocatalyst for Zn–air batteries
(Royal Society of Chemistry, 2020-06-30) Zou, Jizhao; Luo, Qi; Wu, Hongliang; Liu, Shiyu; Lan, Tongbin; Yao, Yuechao; Sial, Muhammad Aurang Zeb Gul; Zhao, Fenglin; Zhang, Qi; Zenga, Xierong
Transition metal selenide-based materials have been demonstrated as promising electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), yet the actual design of a highly efficient and stable electro-catalyst based on these materials still remains a long and arduous challenge. Herein, a predesigned hybrid Zn/Co zeolitic imidazole framework was used to fabricate CoSe2/Co nanoheteroparticles embedded within hierarchically porous Co, N co-doped carbonnanopolyhedra/nanotubes (CoSe2/Co@NC-CNTs) through a facile approach involving controlled carbonization and selenization procedures. As expected, the optimized CoSe2/Co@NC-CNT-1 displayed outstanding electrocatalytic performance for the ORR and OER, with an onset potential of 0.95 V vs. RHE, a half-wave potential of 0.84 V vs. RHE for ORR, and a potential of 1.69 V vs. RHE for OER at 10 mA cm−2. It also exhibited excellent long-term stability and methanol resistance ability, which were superior to commercial IrO2 and the commercial 20 wt% Pt/C catalyst. Notably, the assembled Zn–air battery with CoSe2/Co@NC-CNT-1 showed a low charge–discharge voltage gap (0.696 V at 10 mA cm−2) and a high peak power density (100.28 mW cm−2) with long-term cycling stability. These superior performances can be ascribed to the synergistic effects of the highly active CoSe2/Co nanoheterostructure, hierarchically porous structure with a large surface area, high electrical conductivity and uniform doping of the Co and N
Open Access
Crystallization kinetics and enhanced dielectric properties of free standing lead-free PVDF based composite films
(Elsevier, 2017-06-06) Meng, Nan; Mao, Rui; Tu, Wei; Odolczyk, Katarzyna; Zhang, Qi; Bilotti, Emiliano; Reece, Michael J.
Ferroelectric composites, integrating dielectric ceramic fillers with mechanically flexible polymers, are promising materials for flexible electronic applications. Plenty of research has demonstrated the enhanced dielectric and ferroelectric properties of composite materials. However, the mechanisms responsible for these enhancements are not completely understood. Herein, we used typical dielectric materials, poly(vinylidene fluoride) (PVDF) and BaTiO3 (BTO), to study the effect of a dielectric filler on the crystallization, phase transformation and dielectric properties of PVDF. The crystallization of β-PVDF was not affected by the presence of BTO particles, but small amounts of BTO (<3 vol %) made PVDF crystallize into larger spherulites. This is linked to crystallization kinetic studies, which showed that BTO acted as a nucleation agent for large full ring banded spherulites when its content was less than 1 vol %. Furthermore, solid state drawing in the presence of BTO particles promoted the formation of β-PVDF with more pronounced preferred crystalline orientation at high drawing temperatures (120 °C). The dielectric and ferroelectric properties were enhanced with BTO filling. The 100 °C oriented drawn PVDF tape exhibited a dielectric permittivity of 14 (100 Hz) and remnant polarization of 0.080 C/m2 (10 Hz), which increased to 23 and 0.095 C/m2, respectively, after filling with 5 vol % BTO; neither resulting in high dielectric loss tangent (∼0.02) nor obvious current leakage. Moreover, the coercive field decreased from 80 to 50 kV/mm with increasing BTO content from 0 to 5 vol %.
Open Access
The decrease of depolarization temperature and the improvement of pyroelectric properties by doping Ta in lead-free 0.94Na0.5Bi0.5TiO3-0.06BaTiO3 ceramics
(Elsevier, 2016-12-02) Balakt, Ahmed M.; Shaw, Christopher P.; Zhang, Qi
Ta-doped lead-free 0.94NBT-0.06BT-xTa (x=0.0–1.0%) ceramics were synthesized by a conventional solid-state route. XRD shows that the compositions are at a morphotropic phase boundary where rhombohedral and tetragonal phases coexist. The depolarization temperature (Td) shifted to lower temperature with the increase of Ta content. The pyroelectric coefficient (p) of doped ceramics greatly enhanced compared with undoped material and reached a maximum of 7.14×10−4 C m−2 °C−1 at room temperature (RT) and 146.1×10−4 C m−2 °C−1 at Td at x=0.2%. The figure of merits, Fi and Fv, also showed a great improvement from 1.12×10−10 m v−1 and 0.021 m2 C−1 at x=0.0 to 2.55×10−10 m v−1 and 0.033 m2 C−1 at x=0.2% at RT. Furthermore, Fi and Fv show the huge improvement to 52.2×10−10 m v−1 and 0.48×10−10 m v−1 respectively at Td at x=0.2%. FC shows a value between 2.26 and 2.42 ×10−9 C cm−2 °C−1 at RT at x=0.2%. The improved pyroelectric properties make NBT-0.06BT-0.002Ta ceramics a promising infrared detector material.
Open Access
Densification of lead zirconate titanate sol-gel coatings
(Elsevier Science B.V., Amsterdam., 2006-06-01T00:00:00Z) Khan, Mikael A.; Kurchania, Rajnish; Corkovic, Silvana; Zhang, Qi; Milne, Steven J.
A novel method for the densification of sol-gel films is presented. After elimination of organic decomposition products by heat-treatment at 350 °C and 450 °C, the films are isopressed prior to crystallisation at 550 °C. Consequently, porous lead zirconate titanate films, ~0.7 um in thickness with pore sizes of ~0.1 um could be transformed into dense 0.2 um fil