共查询到20条相似文献,搜索用时 15 毫秒
1.
Chang Won AhnSung Sik Won Aman UllahSun Young Lee Su Dae LeeJi Hye Lee William JoIll Won Kim 《Current Applied Physics》2012,12(3):903-907
0.85Bi0.5Na0.5TiO3-0.15Bi0.5K0.5TiO3 (BNKT15) lead-free thin films were prepared on Pt(111)/TiO2/SiO2/Si(100) substrates by the chemical solution deposition method. BNKT15 are MPB composition in the Bi0.5Na0.5TiO3-Bi0.5K0.5TiO3 (BNT-BKT) system. The maximum piezoelectric coefficient (d33,f) value of BNKT15 thin film is approximately 75 pm/V, which is comparable to that of polycrystalline PZT thin films. These results suggest that BNKT15 thin film can be used as an alternative for PZT films in piezoelectric micro-electromechanical systems. 相似文献
2.
Hongwei Chen Chuanren Yang Chunlin Fu Li Zhao Zhiqiang Gao 《Applied Surface Science》2006,252(12):4171-4177
Barium strontium titanate (BST) thin films were prepared by RF magnetron sputtering. The dielectric constant-voltage curves and the hysteresis loops of BST thin films with different grain sizes and film thicknesses were investigated. When the grain size increases from 12 nm to 35 nm, remarkable increases in dielectric constant and tunability were observed. Above 12 nm, the BST films exhibited size effects, i.e. a decrease in maximal polarization (Pm) and an increase in coercive electric field (Ec) with reduction in grain size. In our investigation, the dielectric constant, tunability and maximal polarization increased as the film thickness increased. Furthermore, the size dependence of the dielectric constant and tunability of Ba0.6Sr0.4TiO3 thin films is determined by that of the maximal polarization and the coercive electric field. 相似文献
3.
Dongxiang ZhouGang Jian Yanan Zheng Shuping GongFei Shi 《Applied Surface Science》2011,257(17):7621-7626
Electrophoretic deposition was utilized for preparation of BaTiO3/CoFe2O4 multiferroic composite thick films on indium-tin oxide substrates. The suspensions for electrophoretic experiments were prepared by dispersing BaTiO3 and CoFe2O4 nanoparticles with different molar ratios into solvents composed of ethanol and acetylacetone. Polyvinyl butyral was added to the suspensions in order to enhance the adhesion and strength of deposit and prevent cracking. The zeta potential values of BaTiO3/CoFe2O4 suspensions were measured to be 26.4-36.9 mV. The experiment results showed that deposited films were obtained only when the applied electric field was larger than a certain critical value. XRD and SEM analysis depicted the presence of constituent phases in composite films. The percolation threshold of composite films was improved through dispersing ferromagnetic phase into ferroelectric phase. Therefore, the ferroelectric properties of composite thick films were maintained when the ferromagnetic properties were enhanced significantly with increasing CFO content. 相似文献
4.
It is shown that different highly oriented Pb(Zr0.52,Ti0.48)O3 films can be obtained on Pt/Ti/SiO2/Si substrate using a sol-gel technique. The effects of pyrolysis temperature on the orientation, phase composition and ferroelectric properties of the films are investigated. It is found the ferroelectric hysteresis loops of (1 1 1)-oriented film, (1 1 1) and (1 0 0) mix-oriented film can both be saturated when the external electric field is large enough, whereas the hysteresis loop of (1 0 0)-oriented film is difficult to saturate. The analysis of X-ray diffraction indicated the possibility of different phase composition in different oriented films under large film residual stress. Higher remnant polarization (53 μC/cm2) for (1 0 0)-oriented film can be attributed to its more tetragonal phase composition, which results in that the in-plane domain switching can continuously occur with external electric field increasing. 相似文献
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The difficulties in synthesizing phase pure BaTiO3 doped-(Na0.5Bi0.5)TiO3 are known. In this work, we reporting the optimized pulsed laser deposition (PLD) conditions for obtaining pure phase 0.92(Na0.5Bi0.5)TiO3-0.08BaTiO3, (BNT-BT0.08), thin films. Dielectric, ferroelectric and piezoelectric properties of BNT-BT0.08, thin films deposited by PLD on Pt/TiO2/SiO2/Si substrates are investigated in this paper. Perovskite structure of BNT-BT0.08 thin films with random orientation of nanocrystallites has been obtained by deposition at 600 °C. The relative dielectric constant and loss tangent at 100 kHz, of BNT-BT0.08 thin film with 530 nm thickness, were 820 and 0.13, respectively. Ferroelectric hysteresis measurements indicated a remnant polarization value of 22 μC/cm2 and a coercive field of 120 kV/cm. The piezoresponse force microscopy (PFM) data showed that most of the grains seem to be constituted of single ferroelectric domain. The as-deposited BNT-BT0.08 thin film is ferroelectric at the nanoscale level and piezoelectric. 相似文献
6.
Da-Yong Lu Tateaki OgataHidero Unuma Xue-Cui LiNa-Na Li Xiu-Yun Sun 《Solid State Ionics》2011,201(1):6-10
In order to clarify whether the mixed valence of Eu2+/Eu3+ exists in a self-compensation mode in Eu-doped BaTiO3, the site occupation and valence state of Eu ions in barium titanate were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), electron spin resonance (ESR), Raman spectroscopy (RS), and dielectric measurements. The results indicate that Eu ions may enter both Ba- and Ti-sites as Eu3+, forming a self-compensation mode with the amphoteric behavior. Self-compensation characteristics of Eu ions in BaTiO3 are reflected by an expansion in unit cell volume, evolution of the 830 cm− 1 Raman band, strong diffusion of the dielectric peak, disappearance of the Eu2+ ESR broad signal, and a g = 2.004 signal independent of temperature. 相似文献
7.
Jian-Jun Gu Guo-Liang ZhaoFu-Wei Cheng Jin-Rong HanLi-Hu Liu Hui-Yuan Sun 《Physica B: Condensed Matter》2011,406(23):4400-4403
Multiferroic thin films with the general formula TiO2/BiFe1−xMnxO3 (x=0.00, 0.05, 0.10 and 0.15) (TiO2/BFMO) were synthesized on Au/Ti/SiO2/Si substrates using a chemical solution deposition (CSD) method assisted with magnetron sputtering. X-ray diffraction analysis shows the thin films contained perovskite structures with random orientations. Compared with BFMO films, the leakage current density of the TiO2/BFMO thin films was found to be lower by nearly two orders of magnitude, and the remnant polarizations were increased by nearly ten times. The enhanced ferroelectric properties may be attributed to the lower leakage current caused by the introduction of the TiO2 layer. The J-E characteristics indicated that the main conduction mechanism for the TiO2/BFMO thin film was trap-free Ohmic conduction over a wide range of electric fields (0-500 kV/cm). In addition, ferromagnetism was observed in the Mn doped BFO thin films at room temperature. The origin of ferromagnetism is related to the competition between distortion of structure and decrease of grain size and decreasing net magnetic moment in films due to Mn doping. 相似文献
8.
W.S. YanR. Zhang Z.L. XieX.Q. Xiu C.Z. ZhaoY.D. Zheng Z.G. Liu 《Physics letters. A》2011,375(22):2189-2192
Impact of anisotropic strains on low-frequency dielectric properties and room-temperature polar phases of SrTiO3 epitaxial thin films is investigated. The dielectric properties show a remarkable change as a function of anisotropic strains. The number of room-temperature polar phases is as twice as that of isotropically strained SrTiO3 thin films. 相似文献
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Chunlin Fu Chuanren Yang Hongwei Chen Liye Hu Linshan Dai 《Applied Surface Science》2005,252(2):461-465
The microstructure and electrical properties of Ba0.6Sr0.4TiO3 thin films have been investigated. Nanometer-sized domains, ranging from 8 to about 30 nm, were observed by piezoresponse force microscopy (PFM). The critical size, below which only single domains exist, is found to be about 31 nm. The film exhibits ferroelectric behavior characterized by polarization hysteresis loop and capacitance-voltage curve. 相似文献
11.
S. Wongsaenmai K. Kanchiang S. ChandarakY. Laosiritaworn S. RujirawatR. Yimnirun 《Current Applied Physics》2012,12(2):418-421
In this study, ceramics in Mn-doped ((Ka0.5Na0.5)0.935Li0.065)NbO3 ceramics (Mn content = 0.25, 0.50, 1.00 and 1.50 mol%) were successfully prepared by the conventional mixed-oxide technique. The crystal structure was identified by XRD as a single-phase perovskite structure with tetragonal symmetry. The valence of Mn ions, characterized by the synchrotron XAS technique, was seen to change from Mn4+ to Mn3+ during the formation of the crystal. The valence state of Mn strongly affected the crystal structure and ferroelectric properties of the ceramics. The ferroelectric parameters show the decrease of remnant polarization and the increase of the coercive field with increasing MnO2 content. The results confirm the Mn3+ in KNNL perovskite lattices, leading to the formation of oxygen vacancies and hardening effects. 相似文献
12.
用脉冲激光沉积技术制备了掺杂纳米金属颗粒Au或Fe的BaTiO3复合薄膜.用透射电子显微镜和x射线光电子能谱表征了金属颗粒的形态和化学态.330—800nm范围的吸收谱研究表明,掺Au颗粒的BaTiO3薄膜在580nm附近有一个明显的共振吸收峰,而掺Fe颗粒的BaTiO3薄膜没有这样的吸收峰.用Mie散射理论对结果进行了分析.
关键词:
复合薄膜
金属颗粒
脉冲激光沉积
吸收谱 相似文献
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Juan Du Guo-Zhong ZangYi Xiu-Jie Yan-Yan WeiYue-Fang Wang 《Physica B: Condensed Matter》2012,407(4):664-667
0.935(K0.5+xNa0.5+x)NbO3-0.065LiSbO3 lead-free piezoelectric ceramics were prepared by normal sintering, and their piezoelectric and dielectric properties were investigated by varying the compensating amount x of alkaline elements (Na and K) addition. It was found that the crystal structure changed from tetragonal to orthorhombic with increasing x from −0.010 to 0.010. An MPB was tailored by optimizing the alkaline elements contents. Enhanced electrical and electromechanical responses of d33=253 pC/N, kp=0.47, kt=0.45 and tanδ=0.027 were obtained in the ceramics with x=0.005. These excellent piezoelectric and electromechanical properties indicate that this system may be an attractive lead-free material for a wide range of electro-mechanical transducer applications. 相似文献
15.
The calcium-substituted barium titanate ceramics were prepared by solid state reaction technique. High-energy ball-milling was used for processing the powder. The microstructure of Ba1−xCaxTiO3 ceramics was investigated by SEM techniques. The microstructure of Ba1−xCaxTiO3 ceramics shows dense and uniform micrograph in all samples and the grain size is large. In this study the quantitative analysis of the ceramographs is shown and the variation of the different parameters with various doping concentration is discussed. Compositional analysis is ascribed to the occupancy of some Ca2+ to the Ti4+ sites. 相似文献
16.
The [(Pb0.90La0.10)Ti0.975O3/PbTiO3]n (PLT/PT)n (n = 1-6) multilayer thin films were deposited on the PbOx(1 0 0)/Pt/Ti/SiO2/Si substrates by RF magnetron sputtering method. The layer thickness of PbTiO3 in one periodicity kept unchanged, and the layer thickness of (Pb0.90La0.10)Ti0.975O3 is varied. The electrical properties of the (PLT/PT)n multilayer thin films were investigated as a function of the periodicity (n) and the orientation. The studied results show that the PbOx buffer layer results in the (PLT/PT)n films’ (1 0 0) orientation, and the (1 0 0)-oriented (PLT/PT)n multilayer thin films with n = 2 exhibit better pyroelectric properties and ferroelectric behavior than those of (PLT/PT)n films with other periodicities and orientations. The underlying physical mechanism for the enhanced electrical properties of (PLT/PT)n multilayer thin films was carefully discussed in terms of the periodicities and orientations. 相似文献
17.
The influence of ferroelectric polarization on the reaction of 2-fluoroethanol on ferroelectric BaTiO3 thin films was characterized. 2-Fluoroethanol was found to absorb dissociatively on the BaTiO3 surface to form an alkoxide that reacts upon heating to produce acetaldehyde, ethylene, and adsorbed fluorine atoms which remain on the surface. Temperature programmed desorption (TPD) studies showed that the activation energy for the production of the acetaldehyde product was a function the orientation of the ferroelectric dipoles with an ∼4 kJ mol−1 higher value on the c+ termination relative to the c− termination. 相似文献
18.
Hong-li GuoGuo Liu Xue-dong LiHai-min Li Wan-li ZhangJian-guo Zhu Ding-quan Xiao 《Applied Surface Science》2011,257(15):6573-6576
The multiferroic (PMN-PT/CFO)n (n = 1,2) multilayered thin films have been prepared on SiO2/Si(1 0 0) substrate with LNO as buffer layer via a rf magnetron sputtering method. The structure and surface morphology of multilayered thin films were determined by X-ray diffraction (XRD) and atom force microscopy (AFM), respectively. The smooth, dense and crack-free surface shows the excellent crystal quality with root-mean-square (RMS) roughness only 2.9 nm, and average grain size of CFO thin films on the surface is about 44 nm. The influence of the thin films thickness size, periodicity n and crystallite orientation on their properties including ferroelectric, ferromagnetic properties in the (PMN-PT/CFO)n multilayered thin films were investigated. For multilayered thin films with n = 1 and n = 2, the remanent polarization Pr are 17.9 μC/cm2 and 9.9 μC/cm2; the coercivity Hc are 1044 Oe and 660 Oe, respectively. In addition, the relative mechanism are also discussed. 相似文献
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