共查询到19条相似文献,搜索用时 57 毫秒
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将600℃退火后的超磁致伸缩材料(Tb0.27Dy0.73)0.3Fe0.7薄膜作为Ni80.2Fe14.1Si0.2Mn0.4Mo5.1三明治膜的基底,制备出四层膜.结果表明:附加的磁致伸缩并没有减小材料的巨磁阻抗(GMI)效应,而由于磁场下磁致伸缩材料的应力效应影响了三明治膜中的各向异性场,使三明治膜的GMI效应增大了4倍.再将制备态的四层膜在280℃下真空退火,退火态四层膜也增大了三明治膜的GMI效应,但可能由于磁致伸缩向磁性层中的扩散,其GMI效应相对于制备态四层膜则有所降低.
关键词:
巨磁阻抗(GMI)效应
三明治膜
TbDyFe薄膜
各向异性场 相似文献
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磁致伸缩材料在传感、控制及能量与信息转换等领域应用前景广阔,此类材料的性能提升及工程应用已成为研究热点,但材料在制备与使用中不可避免会出现缺陷.本文以常用的铁磁性材料铁单质为研究对象,采用分子动力学方法分别建立无缺陷、孔洞缺陷与裂纹缺陷的铁单质磁致伸缩结构模型,分析了缺陷形式对铁单质薄膜磁致伸缩行为的影响,并从微观原子磁矩角度解释缺陷对磁致伸缩行为的影响机理.结果表明:缺陷会对其周围的原子磁矩产生影响,从而影响铁单质薄膜磁致伸缩,其中孔洞形缺陷对磁致伸缩的影响较小,裂纹形缺陷对磁致伸缩的影响较大.裂纹的方向会影响铁单质薄膜的磁致伸缩,与磁化方向平行的裂纹会降低材料在磁化方向上由初始状态至磁化达到饱和的最大磁致伸缩量;与磁化方向垂直的裂纹会提高材料在磁化方向上由初始状态至磁化达到饱和的最大磁致伸缩量. 相似文献
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运用Landau-Devonshire热力学唯像理论,考虑铁电相和铁磁相的电致伸缩、磁致伸缩效应以及产生于铁电/铁磁和薄膜/基底界面的弹性应力作用,两次重整介电和磁作用系数得到了这种多铁系统在Landau自由能函数下的本征二次方磁电耦合形式,从而研究了外延1-3型纳米多铁复合薄膜中极化、磁化随薄膜厚度、温度的变化以及该薄膜中外加电场诱导的磁化变化.结果表明薄膜平面内的应压力的弛豫使得磁化强度和极化强度随薄膜厚度的增加而减少,外加电场不仅能诱导铁电相极化场翻转,而且由于铁电和铁磁相界面竖直方向的弹性耦合导致
关键词:
多铁
磁电效应
磁致伸缩
薄膜 相似文献
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磁致伸缩材料在传感器、位移器件等领域应用前景广阔,对此类材料的制备与实验已成为研究热点,但使用分子动力学方法模拟其磁致伸缩过程中内部磁矩的演化仍缺乏相关研究.本研究以磁致伸缩材料铁单质为研究对象,采用分子动力学方法建立单畴铁单质磁致伸缩模型.分析了铁单质薄膜磁致伸缩行为随初始磁矩的变化,以及在磁场作用下微观原子磁矩的变化与宏观磁致伸缩之间的关系.结果表明:模型磁化构型的演化与磁致伸缩行为有着密切联系,随着外加磁场强度增大,原子磁矩与外加磁场方向相同的区域面积逐渐增大,宏观表现为模型的磁致伸缩随磁场强度增大而伸长,并最终达到饱和,而边界处的原子磁矩是模型是否达到饱和磁致伸缩的关键. 相似文献
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采用射频磁控溅射方法在纯N2气氛中沉积了非晶CNx薄膜样品,并在真空中退火至900 ℃.对高温退火引起的CNx薄膜化学成分、键合结构及其场发射特性方面的变化进行研究.用傅里叶变换红外光谱和x射线光电子能谱分析样品的内部成分及键合结构的变化,其中sp2键及薄膜中N的含量与薄膜的场发射特性密切相关.退火实验的结果表明高温退火可以导致CNx薄膜中N含量大量损失,并在薄膜中形成大量sp2键,这些化学成分及键合结构上的变化将直接影响CNx薄膜的场发射特性.与其他温度退火样品相比,750 ℃退火的样品具有最低的阈值电场,显示出较好的场发射特性. 相似文献
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Muhammad Tariq Saeed Chani Abdullah M. Asiri Kh. S. Karimov Atif Khan Niaz Sher Bhadar Khan Khalid. A. Alamry 《中国物理 B》2013,(11):629-633
This study presents the fabrication and temperature sensing properties of sensors based on aluminium phthalocyanine chloride(AlPcCl)thin films.To fabricate the sensors,50-nm-thick electrodes with 50-μm gaps between them are deposited on glass substrates.AlPcCl thin films with thickness of 50–100 nm are deposited in the gap between electrodes by thermal evaporation.The resistance of the sensors decreases with increasing thickness and the annealing at 100℃ results in an increase in the initial resistance of sensors up to 24%.The sensing mechanism is based on the change in resistance with temperature.For temperature varying from 25℃ to 80℃,the change in resistance is up to 60%.Simulation is carried out and results obtained coincide with experimental data with an error of±1%. 相似文献
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The effects of thermal annealing on the component and microstructure of carbon nitride films deposited by vacuum cathodic arc method are reported. The bonding structure of the films is investigated by Raman spectroscopy, FTIR, XPS and valence band XPS. Upon annealing, the N content of the film drops gradually from original 31.0 to 17.0 at.% at 600 °C. The results of Raman spectroscopy, FTIR and valence XPS demonstrate that the films below 500 °C mainly consist of aromatic cluster component and polymeric component, which is rather stable upon the increasing of anealing temperatures. With the further increasing of the annealing temperatures from 400 to 600 °C, the fraction of polymeric component decreases and the aromatic component develops greatly. Meanwhile the films tend to transform towards the fullerene-like microstructure, which can be seen from the large separation of the N 1s peaks (>2.0 eV). As a result the N sp3 C bonds increase due to the rising of cross-linking between the graphite plane. 相似文献
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Manisree Majumder 《Journal of luminescence》2010,130(8):1497-1503
Nanostructured cadmium sulfide (CdS) thin films have been prepared by chemical bath deposition (CBD) method and after post deposition annealing of the thin films at different temperatures, photoluminescence (PL) property has been studied. The effects of various photoexcitation wavelengths on the PL behaviour of different annealed films of CdS were studied by recording the PL spectra. The intensity of PL, the profile of the PL spectra and the effects of photoexcitation wavelength depend drastically on the temperature of the post deposition annealing of the thin films. The XRD patterns of the films show the presence of both the hexagonal and cubic phases (mixed phases). The emission peak arises from the surface defects of the CdS nanocrystalline thin films. Significant modification in the surface morphology of the CdS films upon annealing has been observed from the FESEM images. The morphology of the thin films is expected to influence the PL behaviour of the CdS thin films. The quantum size effect and size dependant PL have been observed. 相似文献
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R.T. Zhang 《Applied Surface Science》2008,254(21):6697-6700
As a traditional etchant, pure buffered hydrofluoric acid (BHF), does not possess the ability to etch BST thin films annealed at high temperature, even though it works greatly on as-deposited Ba0.5Sr0.5TiO3 (BST) films. In this paper, we developed an etchant by mixing BHF and strong acid (HNO3, HCl, H2SO4 and H3PO4) and use it successfully on BST films annealed with high temperature. The experimental results show that a 1-8 wt% of strong acid acts as an efficient catalyst and the etching speed is significantly improved. The etched BST films show little distortions and smooth etching edges were recorded. 相似文献
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对不同温度下沉积的ZnS薄膜的结晶情况和光学特性进行了研究, 结果表明:沉积温度对ZnS薄膜的物理和光学特性有较大影响, 不同的温度沉积的ZnS薄膜具有不同的择优取向, 牢固度也大不相同; 不同沉积温度下, ZnS薄膜的光学常数也不尽相同. 温度为115 ℃和155 ℃时, ZnS薄膜的物理性能和光学性能较差, 不适合空间用光学薄膜的研制使用. 而190 ℃和230 ℃沉积温度下所得薄膜具有较好的物理和光学性能, 适合于不同要求的空间用薄膜器件的研制使用.
关键词:
硫化锌薄膜
沉积温度
表面形貌
光学常数 相似文献
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The sol–gel spin-coated nickel ferrite (NF), NiFe2O4, thin films were synthesised and the effect of annealing temperature and compositional ratio on different properties of samples were investigated. Electrochemical performance of the films was measured in the presence of KOH and LiClO4/PC electrolyte. Generally, addition of nickel increases the current density. The NF thin films with molar ratio of 0.5 and annealed at 400 °C have the highest charge density value and the highest capacitance in both electrolytes. Annealing temperature had significant effect on electrochemical properties of NF thin films and the diffusion coefficient enhanced by increasing the annealing temperature. X-ray diffraction patterns of prepared samples showed the rhombohedral structure, hematite phase (α-Fe2O3), of iron oxide sample and the presence of inverse spinel structure confirms the formation of NF. Field emission scanning electron microscopy images revealed that the morphology of films changes from larvae shape to granular structure by nickel incorporation and the grain size increased by raising the annealing temperature. The absorption edge of the hematite shift to higher wavelength by annealing and nickel incorporation and band gap narrowing has been occurred. 相似文献
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A new carbon film deposition technique, based upon excimer laser vaporization of graphite in a flowing gas system has been developed. The low temperature vapor (LTV) technique alleviates high temperatures occurring in most other deposition methods. In this technique the UV laser ablation occurs in an inert flowing gas atmosphere. Atoms and molecules evaporated from graphite are cooled by gas entrainment before condensing on a substrate. The resulting films of amorphous carbon or hydrogenated amorphous carbon are free from strain. Measurement of the optical band gap of these films shows that Eg can be controlled by the hydrogen content of the carrier gas. 相似文献
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采用反应磁控溅射法在Si(111)基片上制备了带有Ti缓冲层的高c轴取向ZnO薄膜.通过X射线衍射分析和光致荧光光谱测量,研究了Ti缓冲层厚度和退火处理对ZnO薄膜结晶质量和光致荧光特性的影响.研究结果表明,Ti缓冲层的引入可以有效改善Si基片上ZnO薄膜的发光性能,但缓冲层存在一个最佳的厚度.薄膜应力是影响ZnO薄膜紫外荧光发射性能的重要因素,较小的残余应力对ZnO薄膜的紫外荧光发射是有利的,残余应力的存在可以改变ZnO薄膜紫外荧光发射能量.随着退火温度的增加,薄膜中的张应力增大,导致带隙宽度减小以及激子复合跃迁峰逐渐向低能方向移动.
关键词:
ZnO薄膜
缓冲层
退火处理
应力分析 相似文献