共查询到20条相似文献,搜索用时 15 毫秒
1.
Hai Wen Xiaohui Wang Caifu Zhong Like Shu Longtu Li 《Journal of the American Ceramic Society》2007,90(8):2441-2445
The compositionally graded BiScO3 –PbTiO3 (BSPT) thin films were fabricated on Pt/Ti/SiO2 /Si by a sol–gel method. For the up-graded thin film, the PbTiO3 content increased from the film–substrate interface to the surface of the film, while the down-grade thin film showed the opposite trend. The graded thin films exhibited single-phase structures and dense microstructures. The dielectric and ferroelectric properties of the thin films were investigated. The results showed that the compositionally graded BSPT thin films had similar remanent polarization value but a higher dielectric constant, dielectric tunability, and piezoelectric coefficient d 33 compared with the homogeneous thin film with a composition of 0.36BiScO3 –0.64PbTiO3 at the morphotropic phase boundary. 相似文献
2.
Yunyi Wu Duanming Zhang Jun Yu Yunbo Wang 《Journal of the American Ceramic Society》2009,92(2):501-505
Praseodymium doped Bi4 Ti3 O12 (BTO) thin films with composition Bi3.63 Pr0.3 Ti3 O12 (BPT) were successfully prepared on Pt/Ti/SiO2 /Si substrates by RF-magnetron sputtering method at substrate temperatures ranging between 500° and 750°C. The structural phase and orientation of the deposited films were investigated in order to understand the effect of the deposition temperature on the properties of the BPT films. As the substrate temperature was increased to 700°C, the films started showing a tendency of assuming a c -axis preferred orientation. At lower temperatures, however, polycrystalline films were formed. The Pt/BPT/Pt capacitor showed an interesting dependence of the remnant polarization (2 P r ) as well as dc leakage current values on the growth temperature. The film deposited at 650°C showed the largest 2 P r of 29.6 μC/cm2 . With the increase of deposited temperature, the leakage current densities of films decreased at the same applied field and the film deposited at 750°C exhibited the best leakage current characteristics. In addition, the ferroelectric fatigue and Raman measurements were carried out on the as-prepared, postannealed in air and postannealed in oxygen BPT films. It was revealed that the BPT film postannealed in air exhibited the weakest fatigue-resistance characteristics and highest frequency shifted Raman vibration modes, indicating the highest oxygen vacancy concentration in this film. 相似文献
3.
BiScO3 –PbTiO3 (BSPT) thin films near the morphotropic phase boundary were successfully fabricated on Pt(111)/Ti/SiO2 /Si substrates via an aqueous sol–gel method. The thin films exhibited good crystalline quality and dense, uniform microstructures with an average grain size of 50 nm. The dielectric, ferroelectric, and piezoelectric properties of the sol–gel-derived BSPT thin films were investigated. A remanent polarization of 74 μC/cm2 and a coercive field of 177 kV/cm were obtained. The local effective piezoelectric coefficient d * 33 was 23 pC/N at 2 V, measured by a scanning probe microscopy system. The dielectric peak appeared at 435°C, which was 80°C higher than that of Pb(Ti, Zr)O3 thin films. 相似文献
4.
Jang-Sik Lee Q. X. Jia Jung-Ho Park Seung-Ki Joo Woo Seok Yang Nam Kyeong Kim Seung Jin Yeom Jae Sung Roh 《Journal of the American Ceramic Society》2004,87(4):720-723
Ferroelectric SrBi2 (Ta,Nb)2 O9 (SBTN) thin films were deposited on Pt (200 nm)/TiO x (40 nm)/SiO2 (100 nm)/Si substrates by metal-organic decomposition. The effects of bombardment from accelerated argon and oxygen ions on the properties of SBTN thin films were investigated. It was found that the argon ion bombardment could decrease the crystallization temperature owing to the increase of internal energy of the films. Also, the oxygen vacancies at the interface between the SBTN film and platinum bottom electrode or at grain boundaries in the film were passivated through the oxygen ion treatment, resulting in the improved electrical properties. By optimizing the process parameters and using bombardment of accelerated argon and oxygen ions, SBTN films with good ferroelectric and electrical properties could be obtained, at a temperature as low as 650°C. 相似文献
5.
Qifa Zhou Qingqi Zhang Baomin Xu Susan Trolier-McKinstry 《Journal of the American Ceramic Society》2002,85(8):1997-2000
Ferroelectric 0.7Pb(Mg1/3 Nb2/3 )O3 –0.3PbTiO3 (PMN-PT) thin films were deposited on ZrO2 /SiO2 /silicon substrates using a chemical-solution-deposition method. Using a thin PZT film as a seed layer for the PMN-PT films, phase-pure perovskite PMN-PT could be obtained via rapid thermal annealing at 750°C for 60 s. The electrical properties of in-plane polarized thin films were characterized using interdigitated electrode arrays on the film surface. Ferroelectric hysteresis loops are observed with much larger remanent polarizations (∼24 μC/cm2 ) than for through-the-thickness polarized PMN-PT thin films (10–12 μC/cm2 ) deposited on Pt/Ti/Si substrates. For a finger spacing of 20 μm, the piezoelectric voltage sensitivity of in–plane polarized PMN-PT thin films was ∼20 times higher than that of through-the-thickness polarized PMN-PT thin films. 相似文献
6.
Jia Li Jun Yu Gang Peng Yunbo Wang Wenli Zhou 《Journal of the American Ceramic Society》2007,90(10):3220-3223
The effect of a 20-nm thick TiO2 seeding layer on the growth of a Bi3.15 Nd0.85 Ti3 O12 (BNT) thin film on Pt(111) thin-film substrates has been studied. Under otherwise identical deposition process conditions, the BNT film could be turned from a highly random orientation to a (200) preference orientation by adding the seeding layer. Field-emission scanning electron microscope result reveals that the BNT thin film with the TiO2 seeding layer is composed of fine grains with smaller sizes about 80–150 nm in diameter. The P r and E c values of the BNT thin film and BNT film with the TiO2 seeding layer were 36 and 16 μC/cm2 , and 96.9 and 92 kV/cm at a voltage of 12 V, respectively. The fatigue test exhibited a very strong fatigue endurance up to 109 cycles for both films. The leakage current densities were generally in the order of 10−6 –10−5 A/cm2 for both samples. 相似文献
7.
Kazumi Kato Can Zheng Jeffrey M. Finder Sandwip K. Dey Yasuyoshi Torii 《Journal of the American Ceramic Society》1998,81(7):1869-1875
Precursors for layer-structured perovskite thin films of SrBi2 Ta2 O9 (SBT) and SrBi2 Nb2 O9 (SBN) were prepared by the reactions of a strontium-bismuth double methoxyethoxide and tantalum or niobium methoxyethoxide in methoxyethanol, followed by partial hydrolysis. Several spectroscopic techniques, such as 1 H-, 13 C-, and 93 Nb-NMR (nuclear magnetic resonance), and Fourier-transform infrared spectroscopy were used to analyze the arrangement of the metals and oxygen in the precursor molecules. The precursors contained Sr-O-M (where M is Ta or Nb) bonds (i.e., a strontium is connected to two MO6 octahedra) and Sr-O-Bi bonds with a bismuth atom bonded to the oxygens of the MO6 octahedron. The arrangement of metals and oxygens was considered to be similar to the layer-structured perovskite crystal sublattice. As a result, the sol-gel-derived SBT thin films crystallized, by rapid thermal annealing in an oxygen atmosphere below 550°C, and they exhibited preferred (115) orientation. The crystallinity improved and the crystallite size increased with temperature up to 700°C. In the case of SBN thin films, a low heating rate (2°C/min) was necessary for the control of the crystallographic (115) orientation, whereas a rate of 200°C/s (rapid thermal annealing) produced films that exhibited c -axis orientation. The (115) SBT thin film, heated to 700°C, exhibited improved ferroelectric properties. 相似文献
8.
Jiwei Zhai Xi Yao Zhengkui Xu Haydn Chen 《Journal of the American Ceramic Society》2006,89(1):354-357
Pb0.6 Sr0.4 TiO3 (PST) ferroelectric thin films were prepared on two different substrates by sol–gel methods. Films derived on the LaNiO(LNO)/Pt/Ti/SiO2 /Si substrates showed a strong (100) preferred orientation. The PST thin films grown on the LNO/Pt/Ti/SiO2 /Si(100) substrate showed a non-uniform rounded grain size distribution and have a larger polarization and lower coercive field E c . The dependence of electrical properties derived on the Pt/Ti/SiO2 /Si and LNO/Pt/Ti/SiO2 /Si substrates has been studied, with a focus on the change of dielectric constant versus direct current (DC) bias field. The dielectric and ferroelectric properties of the Pb0.6 Sr0.4 TiO3 thin films deposition on two kinds of substrates were investigated as a function of temperature, frequency and DC bias field. 相似文献
9.
Jeong Hwan Park Dong Heon Kang Ki Hyun Yoon 《Journal of the American Ceramic Society》1999,82(8):2116-2120
0.5Pb(Mg1/3 Nb2/3 )O3 -0.5PbTiO3 thin films were prepared on Pt(111)/Ti/SiO2 /Si(100) substrates by varying the film formation procedures and heating processes. Depending on the multilayer film formation and appropriate heating process, the films were grown with a preferential orientation. The films showed a (100)-preferred orientation and large grain-size distribution when they were directly heat-treated after deposition of amorphous layers. The films showed a (111)-preferred orientation and small grain-size distribution when formed layer-by-layer or directly heating amorphous thin films with a perovskite seed layer. These results were explained by the effect of a seed layer. Saturation polarization of the (111)-preferred films was ∼35 µC/cm2 , which was somewhat higher than that of the (100)-preferred film. In contrast, the dielectric constant of the (100)-preferred film was ∼1600, which was larger than that of the (111)-preferred film. 相似文献
10.
Ferroelectric thin films of bismuth-containing layered perovskite Bi4 Ti3 O12 have been fabricated by a metalorganic decomposition (MOD) method. Crack-free and crystalline films of ∼5000 Å thickness have been deposited on Pt/Ti/SiO2 /Si substrates. Different heat treatments have been studied to investigate the nucleation and growth of perovskite Bi4 Ti3 O12 crystallites. If the same composition and final annealing temperature are used, films with different orientations are obtained by different heating schedules. These films show a large anisotropy in ferroelectric properties. Theoretical considerations are presented to suggest that nucleation control is responsible for texture and grain-size evolution. Moreover, the origin of the ferroelectric anisotropy is rooted in the two-dimensional nature of layered polarization. 相似文献
11.
Wen Gong Jing-Feng Li Xiangcheng Chu Longtu Li 《Journal of the American Ceramic Society》2004,87(6):1031-1034
Lead magnesium niobium titanate (PMNT) thin films with a composition near the morphotropic phase boundary were prepared on conventional Pt(111)/Ti/SiO2 /Si substrates using a modified sol-gel process. A PbO seeding layer was introduced to the interface between the PMNT layer and the substrate to enhance the [001]-preferential orientation of the PMNT film. Single-phase perovskite PMNT films with highly [001]-preferential orientation were obtained at reduced annealing temperatures compared with the PMNT films directly deposited on the same substrates. The dielectric and ferroelectric properties of the prepared PMNT films were evaluated as a function of annealing temperature. 相似文献
12.
Lead-free (K0.5 Na0.5 )NbO3 (KNN) thin films were prepared on Pt/Ti/SiO2 /Si substrates by a sol–gel processing method, and titanium diffusion from the substrates into the KNN films under different thermal treatment conditions were investigated by the secondary ion mass spectroscopy depth profile and X-ray photoelectron spectroscopy surface analysis. Titanium diffusion was evident in all the KNN thin films, which was further aggravated not only by increasing the annealing temperature, but also surprisingly by higher ramping rate attributed to the resulting larger grain boundaries. The pronounced effects of the titanium diffusion and the resulting substitution of Ti4+ for Nb5+ with different valence states on the composition, structure, and electrical properties of the KNN thin films are analyzed and discussed. The results showed that the Ti diffusion from the substrate played a crucial role in affecting the structure and electrical properties of the ferroelectric KNN thin films deposited on Pt/Ti/SiO2 /Si substrate. 相似文献
13.
Jingsong Liu Shuren Zhang Chengtao Yang Linshan Dai 《Journal of the American Ceramic Society》2005,88(1):85-88
Ferroelectric SrBi1.4 La0.6 Ta2 O9 (SBLT) thin films were grown onto Pt/Ti/SiO2 /Si substrates by pulsed-laser deposition. With the aid of X-ray diffractometry, piezoresponse scanning probe microscopy, and ferroelectric-property measurements, a correlation between microstructure, as well as domain structure and ferroelectric properties, was established. Excluding the effect of preferential orientation on ferroelectric properties, the increase in remanent polarization was attributed to distortion of the perovskite-like sublattice and atom displacement. Despite the co-instantaneous observation of a 90° domain and slight fatigue behavior in the SBLT films, the 90° domain-wall clamping did not seem to account for the fatigue in the SBLT films. Instead, strain-stress aggravation of the SBLT sublattice, due to the substitution of La3+ into Bi3+ sites, decreased the self-regulated flexibility of the (Bi2 O2 )2+ layers and caused fatigue in the SBLT. 相似文献
14.
Tadasu Hosokura Keisuke Kageyama Hiroshi Takagi Yukio Sakabe 《Journal of the American Ceramic Society》2009,92(1):253-255
Epitaxially grown single-crystal perovskite (100) three-axis-oriented (Ba0.7 Sr0.3 )TiO3 thin films were prepared on a (100) platinum-coated (100) magnesium oxide (MgO) single-crystal substrate by the chemical solution deposition method using a solution derived from Ba(CH3 COO)2 , Sr(CH3 COO)2 , and Ti(O- i -C3 H7 )4 .
The growth of the film was found to depend on the annealing condition. A (Ba,Sr)TiO3 thin film annealed at 1073 K was found to be a single crystal by transmission electron microscope. The single-crystal film exhibited a (100) three-axis orientation that followed the (100) orientation of the Pt substrate, as observed from an X-ray pole figure measurement and selected area electron diffraction patterns. 相似文献
The growth of the film was found to depend on the annealing condition. A (Ba,Sr)TiO
15.
Shin-ichi Hirano Toshinobu Yogo Ko-ichi Kikuta Wataru Sakamoto Hirosada Koganei 《Journal of the American Ceramic Society》1996,79(12):3041-3044
Nd: YVO4 powders and thin films were successfuly synthesized by the sol–gel method using metal alkoxides. A homogeneous and stable solution was prepared by the reaction of Y(OEt)3 , VO(O i Pr)3 , and Nd(OEt)3 in 2-methoxyethanol. The precursor was a mixture of vanadium and yttrium double alkoxide. Precursor films were prepared by dip coating and crystallization to single-phase YVO4 at 500°C. Nd:YVO4 films were crystallized with (200) preferred orientation on glass substrates, which showed the characteristic optical absorption of neodymium. 相似文献
16.
Thin films of Pb(Mg,Zn)1/3 Nb2/3 O3 (PMZN) were fabricated by spin casting the partially hydrolyzed Pb-Mg-Zn-Nb-O complex alkoxide sols on (111)Pt-coated MgO (100) planes. A strong preferential orientation of (100) perovskite was observed in the thin film derived from the sol exhibiting pseudoplastic behavior. A small-angle X-ray scattering experiment in the Porod region was performed to correlate the observed preferential orientation with the network structure of precursor in the PMZN sol. It was shown that weakly branched precursor systems led to highly oriented perovskite grains after thin-film formation. The highly (100) oriented PMZN film exhibited a larger pyroelectric coefficient (>2 μC/(cm2 -K)) and pyroelectric figure-of-merit ( F D > 4 × 101–4 Pa−1/2 ) than the PMZN thin film having randomly oriented grains. 相似文献
17.
Yoshiaki Kinemuchi Ping Hua Xiang Hisashi Kaga Koji Watari 《Journal of the American Ceramic Society》2007,90(9):2753-2758
The preferred orientation of thick films prepared by paste printing is rarely observed because of their bulky polycrystalline nature. We found that a Bi4 Ti3 O12 thick film with a thickness of ca. 20 μm showed c -axis-preferred orientation. Initially, the texture of the screen-printed film was found to have a random orientation, which was attributed to the equiaxed particle shape of the raw powder synthesized by the co-precipitation method. During subsequent heating, c -axis orientation emerged in which the degree of orientation was proportional to the film density. Analysis of the orientation distribution revealed that the progress of texturing was attributed to the film deformation, indicating that anisotropic shrinkage and morphological changes in particles during heating influenced the preferred orientation. 相似文献
18.
Highly (001)-oriented (Pb0.76 Ca0.24 )TiO3 (PCT) thin films were grown on Pt/Ti/SiO2 /Si substrates using a sol–gel process. The PCT film with a highly (001) orientation showed well-saturated hysteresis loops at an applied field of 800 kV/cm, with remanent polarization ( P r ) and coercive electric field ( E c ) values of 23.6 μC/cm2 and 225 kV/cm, respectively. At 100 kHz, the dielectric constant and dielectric loss values of these films were 117 and 0.010, respectively. The leakage-current density of the PCT film was 6.15 × 10−8 A/cm2 at 5 V. The pyroelectric coefficient ( p ) of the PCT film was measured using a dynamic technique. At room temperature, the p values and figures-of-merit ( F D ) of the PCT film were 185 μC/m2 K and 1.79 × 10−5 Pa−0.5 , respectively. 相似文献
19.
Bo-Yun Jang Young-Hun Jeong Suk-Jin Lee Kyong-Jae Lee Sahn Nahm Ho-Jung Sun Hwack-Joo Lee 《Journal of the American Ceramic Society》2005,88(5):1209-1212
BaTi4 O9 thin films were grown on a Pt/Ti/SiO2 /Si substrate using rf magnetron sputtering and the structure of the thin films were then investigated. For the films grown at low temperature (≤350°C), an amorphous phase was formed during the deposition, which then changed to the BaTi5 O11 phase when the annealing was conducted below 950°C. However, when the annealing temperature was higher than 950°C, a BaTi4 O9 phase was formed. On the contrary, for the films grown at high temperature (>450°C), small BaTi4 O9 grains were formed during the deposition, which grew during the annealing. The homogeneous BaTi4 O9 thin films were successfully grown on Pt/Ti/SiO2 /Si substrate when they were deposited at 550°C and subsequently rapid thermal annealed at 900°C for 3 min. 相似文献
20.
Pb(Mg1/3 Ta2/3 )0.7 Ti0.3 O3 thin films of single perovskite phase were successfully synthesized by using the RF sputtering deposition technique, followed by post-thermal annealing. While the perovskite structure of Pb(Mg1/3 Ta2/3 )0.7 Ti0.3 O3 is rather unstable, phase evolution in the thin films was manipulated by controlling both working pressure during the sputtering process and post-thermal annealing temperature. The desirable perovskite phase was promoted by increasing the working pressure in the range of 10–25 mTorr, followed by thermal annealing at 600°C. The ferroelectric, dielectric, and polarization behaviors of Pb(Mg1/3 Ta2/3 )0.7 Ti0.3 O3 films were characterized over a wide range of frequencies. They are strongly affected by the film thickness, where the relative permittivity and remanent polarization increase, while the coercive field decreases with increasing film thickness in the range of 115–360 nm. 相似文献