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铁电薄膜及铁电存储器的研究进展 总被引:1,自引:0,他引:1
铁电薄膜是具有铁电性且厚度尺寸为数纳米到数微米的薄膜材料,因其在非挥发性铁电随机存储器方面的潜在应用而受到广泛关注.综述了新型无铅、无疲劳Bi4Ti3O12(BIT)基铁电薄膜材料的制备和改性及性能表征方法,阐述了铁电薄膜的3种失效机制及铁电薄膜存储器的研究现状,最后提出了铁电薄膜及存储器今后可能的研究方向. 相似文献
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Forming limits of nickel coating on right region 总被引:1,自引:0,他引:1
The forming limits of nickel coating on the right region were studied, so as to direct the preparation of the material and help the production of workpieces. The electrodeposited nickel coating was prepared on steel substrate to form advanced structures, and its plastic instability was investigated by the Swift Plastic Instability Theory. By using the compound law for laminated sheet metals, explicit equations for the calculation of the instable eigen values were deduced. The forming limit diagrams of the nickel coating on the right region were plotted. It is exhibited that the forming limit of the coating sheet is between the forming limits of the individual nickel coating and steel substrate. The forming limit of the nickel coating is not so good as that of the steel substrate, and the forming limit strain of the coating sheet tends to diminish with the increase of thickness of the coating. The greater the normal anisotropic coefficient of the materials is, the better the forming limit is. 相似文献
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铁电薄膜在外加力场,电场和温度场的作用下表现出明显的非线性,为了更好的描述这种现象,本文提出了一个热-电-力耦合场铁电薄膜下的畴变模型。该模型基于细观力学模型,认为电畴自由能的改变提供电畴翻转的动力,且180°电畴翻转由两步90°翻转构成。在本构关系中加入了铁电薄膜制备过程中产生的残余应变项,以区别于块体铁电材料,通过该模型计算出了铁电薄膜在不同外场下的响应,结果与实验和其他模型的结果较为符合。 相似文献
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Thin films of Nd^3+/V^5+-cosubstituted bismuth titanate, (Bi3.sNd0.5)( Ti2.96V0.04)O12 (BNTV), were fabricated on the Pt(111)/Ti/SiO2/Si(100) substrates by a chemical solution deposition technique and annealed at different temperatures of 650, 700, 750 and 800 ℃. The surface morphology and ferroelectric properties of the samples were studied in detail. The result shows that the film annealed at 800 ℃ indicates excellent ferroelectricity with a remanent polarization of 2Pr=40.9 i.tC/cm^2, a coercive field (Ec) of 114 kV/cm at an applied electrical field of 375 kV/cm. The substitution of Ti-site ion by V^5+ ions could improve the upper limit of the optimal annealing temperature by decreasing the space charge density in BNT thin film. Additionally, the mechanism concerning the dependence of ferroelectric properties of BNTV thin films on the annealing temperature was discussed. 相似文献
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对铋层状钙钛矿结构钛酸铋无铅铁电薄膜的制备、改性、失效行为,以及钛酸铋-铁酸钴多铁复合材料进行了研究。通过分析A位和B位离子的极化率和半径关系,设计了一系列复合掺杂钛酸铋基无铅铋层状钙钛矿铁电体系,并制备出了一系列性能优良的单掺杂和复合掺杂的钛酸铋基无铅铁电薄膜,结果表明A位La~(3 )、Nd~(3 )、Eu~(3 )掺杂,B位V~(5 )、Zr~(4 )、Mn~(4 )都可以明显提高薄膜的性能,特别是A位Nd~(3 )掺杂可以很好地提高剩余极化强度和抗疲劳性,B位Mn~(4 )掺杂可以降低矫顽场和漏电电流,有望突破无铅铁电薄膜的应用瓶颈;同时,研究了铁电薄膜及其在辐照条件下的疲劳、保持性能损失和印记失效等失效行为,提出了一个能合理解释印记失效的双界面层的理论模型;还利用化学溶液沉积法制备了不同复合结构(颗粒复合和层状复合)的Nd掺杂钛酸铋/铁酸钴多铁薄膜,并研究了不同复合结构中的磁电耦合效应,研究发现在铁电/铁磁多铁复合材料中,铁电/铁磁界面处两种不同材料之间的原子相互耦合对磁电耦合效应具有很大的贡献。 相似文献
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The electroless Ni-P-SiC composite coatings were prepared and the influence of vacuum heat treatment on its structure and properties was analyzed. The Ni-P-SiC composite coatings were characterized by morphology, structure and micro-hardness. The morphology and structure of the Ni-P-SiC composite coatings were studied by scanning electron microscopy (SEM) and X-ray diffractometry (XRD), respectively. A great deal of particles incorporation and uniform distribution were found in Ni-P-SiC composite coatings. XRD results show a broad peak of nickel and low intensity SiC peaks present on as-deposited condition. Micro-hardness of as-deposited Ni-P-SiC composite coatings is improved greatly, and the best micro-hardness is obtained after heat treatment in a high vacuum at 400 ℃. 相似文献
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