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稀土发光材料已在众多领域获得广泛的应用,并且已成为稀土应用的主要领域之一.本文归纳了白光LED用稀土荧光粉、稀土光转换材料、稀土上转换发光材料、稀土纳米发光材料、真空紫外发光材料、稀土配合物电致发光材料和稀土闪烁体等的研究最新进展,并对未来发展趋势进行了展望. 相似文献
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介绍了相变存储材料的工作原理与其工作性能之间的对应关系,相变存储材料的开发与材料性能要求密不可分,在分析当前主流相变存储材料Ge2 Sb2 Te5的优点与不足的基础上,指出无Te富Sb为未来相变存储材料体系的研究方向.控制相变行为是实现相变存储技术商业化的关键,材料的微观结构和相变机制决定了相变存储材料的相变行为,而计算材料学是研究相变存储材料微观结构与相变机制之间联系的必要手段.运用第一性原理动态模拟相变存储材料的相变过程,可以弥补静态结构分析的不足,推动对快速可逆相变机理动态过程的理解运用,同时为进一步研究相变存储材料提供借鉴. 相似文献
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在5G通信时代,体声波(BAW)滤波器件成为实现高性能射频(RF)滤波的有效解决方案。在当前BAW器件发展最成熟的薄膜体声波谐振器(FBAR)技术和专利被少数几家公司持有的大环境下,对压电薄膜生长、器件的制备工艺等方面进行突破,形成独有的BAW器件技术路线显得尤为重要。本文综述了AlN薄膜的生长、AlN材料在BAW滤波器件的发展、基于AlN的BAW器件的制备及其应用。在国内研究者的努力下,基于单晶AlN的体声波谐振器(SABAR)器件,通过在材料生长方法及制备工艺上的独立自主创新,不仅使BAW滤波器件的性能得到了进一步提升,也给受到国外掣肘的国内射频滤波行业带来了一条摆脱国外“卡脖子”问题的新路线。 相似文献
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A. Moses Ezhil Raj L. C. Nehru M. Jayachandran C. Sanjeeviraja 《Crystal Research and Technology》2007,42(9):867-875
Transparent dielectric thin films of MgO has been deposited on quartz substrates at different temperatures between 400 and 600°C by a pneumatic spray pyrolysis technique using Mg(CH3COO)2·4H2O as a single molecular precursor. The thermal behavior of the precursor magnesium acetate is described in the results of thermogravimetry analysis (TGA) and differential thermal analysis (DTA). The prepared films are reproducible, adherent to the substrate, pinhole free and uniform. Amongst the different spray process parameters, the substrate temperature effect has been optimized for obtaining single crystalline and transparent MgO thin films. The films crystallize in a cubic structure and X‐ray diffraction measurements have shown that the polycrystalline MgO films prepared at 500°C with (100) and (110) orientations are changed to (100) preferred orientation at 600°C. The MgO phase formation was also confirmed with the recorded Fourier Transform Infrared (FTIR) results. The films deposited at 600°C exhibited highest optical transmittivity (>80%) and the direct band gap energy was found to vary from 4.50 to 5.25 eV with a rise in substrate temperature from 500 to 600°C. The measured sheet resistance and the resistivity of the film prepared at 600°C were respectively 1013Ω/□ and 2.06x107Ω cm. The surface morphology of the prepared MgO thin films was examined by atomic force microscopy. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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The crystal structure, surface morphology, compositional homogeneity and electrical properties of barium strontium titanate (BST) thin films are investigated. The films were deposited on bare silicon and platinum coated silicon substrates by spin coating process. The precursor solution with Ba/Sr ratio 70/30 was prepared by sol‐gel synthesis using metal alkoxides. The crystalline nature and morphology of the films are found to be strongly influenced by the heating cycle adopted to form the Ba0.7Sr0.3TiO3 layer. The elemental composition analysis on the surface and in‐depth confirms the stoichiometry of the films. The dielectric constant at 100 kHz and dissipation factor at room temperature is found to be 120 and 0.0236 for the films with 400nm thickness annealed at 700°C for 2 hrs. The leakage current density of the film is found to be 4x10‐8 A/cm2 from I‐V measurements. 相似文献
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采用固相反应法合成具有焦绿石立方结构的Bi1.5ZnNb1.5O7(BZN)陶瓷靶材,采用脉冲激光沉积法在Pt/SiO2/Si(100)基片上制备立方BZN薄膜。研究了沉积氧压的变化对薄膜的结晶性能,微观形貌以及介电性能的影响。结果表明:沉积的BZN薄膜都呈现出立方焦绿石单相结构,但是薄膜的取向随氧压变化而变化。当沉积氧压为10 Pa时,薄膜的(222)晶面拥有最强的择优取向。随着氧压的升高,BZN薄膜的介电常数明显降低。在10 Pa氧压下沉积的BZN薄膜展示出介电可调特性为5%(500 kV/cm)。 相似文献
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本文采用溶胶-凝胶法在Pt(111)/TiO2/SiO2/Si衬底上制备了(Ba0.6Sr0.4)1-xCaxTiO3(BSCT)(x=0,0.1,0.2,0.3,0.4)薄膜.XRD及SEM结果表明表明,薄膜结晶良好,形成单一的钙钛矿结构,没有明显的裂缝.薄膜厚度大约为500nm.从介电常数和直流偏压电场的关系曲线上并没有滞后现象,这说明BSCT薄膜处于顺电相.随着x的增加,薄膜的介电常数、介电损耗和调谐率都有所下降,而优值有所提高.J-V特性表明Ca的加入显著降低了薄膜的漏电流. 相似文献
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掺杂VO2薄膜的相变机理和研究进展 总被引:1,自引:0,他引:1
掺杂VO2薄膜是一种具有相变特性的功能材料,具有广阔的应用前景.本文综述了掺杂VO2薄膜的相变机理、制备方法和应用前景,并指出掺杂VO2薄膜的发展趋势,以期更好地探讨掺杂VO2薄膜的应用研究. 相似文献
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T. K. Subramanyam B. Srinivasulu Naidu S. Uthanna 《Crystal Research and Technology》1999,34(8):981-988
Zinc oxide films were deposited on glass substrates in argon and oxygen atmosphere by dc reactive magnetron sputtering using a metallic zinc target. The influence of oxygen pressure and substrate temperature on the structure and optical properties of the films were systematically investigated and optimised the deposition parameters to prepare single phase zinc oxide films with preferred (002) orientation. At an optimum oxygen pressure of 1x10-3 mbar and substrate temperature of 663 K, the films exhibited an optical transmittance of 83% with a band gap of 3.28 eV. 相似文献
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太阳电池窗口层材料Sc掺杂ZnO薄膜的抗腐蚀性研究 总被引:1,自引:0,他引:1
用于太阳电池窗口层的材料必须具有好的耐蚀性.利用射频磁控溅射的方法分别在300℃、350℃、400℃、450℃的沉积温度下制备透明导电Sc掺杂ZnO薄膜(SZO).用X射线衍射仪对样品的结构进行表征.结果表明,所有SZO薄膜均为六角纤锌矿结构,在(002)衍射峰位上相对于纯ZnO粉末有微小的偏移.用动电位扫描极化曲线和交流阻抗谱表征SZO薄膜的耐腐蚀性能,研究结果表明随沉积温度的升高,SZO薄膜的耐腐蚀性增强.在可见光范围内SZO薄膜透过率达85;以上,经3.5;的NaCl溶液腐蚀24h后薄膜透过率仍在80;以上. 相似文献