共查询到19条相似文献,搜索用时 187 毫秒
1.
利用X射线衍射(XRD)和X射线吸收近边结构(XANES)方法研究了在Si(100)衬底上及600℃温度条件下用分子束外延(MBE)共蒸发方法生长的MnxSi1-x磁性薄膜的结构.由XRD结果表明,只有在高Mn含量(8%和17%)样品中存在着Mn4Si7化合物物相.而XANES结果则显示,对于Mn浓度在0.7%到17%之间的MnxSi1-x样品,其Mn原子的XANES谱表现出了一致的谱线特征.基于多重散射的XANES理论计算进一步表明,只有根据Mn4Si7模型计算出的理论XANES谱才能够很好的重构出MnxSi1-x样品的实验XANES谱.这些研究结果说明在MnxSi1-x样品中,Mn原子主要是以镶嵌式的Mn4Si7化合物纳米晶颗粒存在于Si薄膜介质中,几乎不存在间隙位和替代位的Mn原子. 相似文献
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采用固相反应法, 制备了钙钛矿结构氧化物LaFe1-xCrxO3较宽范围内(x=0.0—0.7)的系列单相样品, 并测量了各样品的X射线衍射谱(XRD)和扩展X射线吸收精细结构(EXAFS)谱. 通过对XRD的分析样品均为钙钛矿结构正交相, 同时晶格常数随着掺杂量x的增加而减小. 通过对EXAFS的分析和研究得到在LaFe1-xCrxO3氧化物中Fe-O键长和Fe-La键长随掺杂浓度x的变化, 发现Fe-La键长发生比较大的变化, 说明La在体系掺杂中对结构的稳定起到重要作用. 相似文献
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Ghulam Murtaza Rai Muhammad Azhar Iqbal Yong-bing Xu Iain Gordon Will Qasim Mahmood 《化学物理学报》2012,25(3):313-317
采用热蒸镀技术和后续氨退火制备了Ho掺杂GaN稀磁半导体薄膜. X射线衍射分析表明,所有的峰属于六角纤锌矿结构. 利用扫描电子显微镜和能量色散谱分别进行了表面形貌和成分分析. 用振动样品磁强计在室温测定了Ga1-xHoxN(x=0.0,0.05)的室温铁磁性. 磁性测量结果表明,未掺杂薄膜GaN具有抗磁性行为,而Ho掺杂Ga0.95Ho0.05N的薄膜表现出铁磁行为. 相似文献
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利用电子回旋共振-等离子体增强金属有机物化学气相沉积 (ECR-PEMOCVD)方法,采用二茂锰(Cp2Mn)作为Mn源,高纯氮气作为氮源,三乙基镓(TEGa)作为Ga源,在蓝宝石(α-Al2O3)(0001)衬底上外延生长GaMnN稀磁半导体薄膜.反射高能电子衍射(RHEED)、X射线衍射(XRD)、原子力显微镜(AFM)表征了GaMnN薄膜的晶体结构和表面形貌.GaMnN薄膜均表现出良好的(0002)择优取向,表明制备的薄膜倾向于 相似文献
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Ghulam Murtaza Rai Muhammad Azhar Iqbal Yongbing Xu Iain Gordon Will Wen Zhang 《化学物理学报》2011,24(3):353-357
研究Ho3+掺杂对氧化锌半导体材料的微结构和磁学性质影响. 利用热蒸发技术制备了一系列沉积在Si(100)衬底的Zn1-xHoxO(x=0.0、0.04、0.05)薄膜. X射线光谱、表面形貌以及磁性的实验结果表明,Ho3+掺杂对ZnO薄膜材料的性能影响很大. X射线衍射图显示峰位出现高角度转变并且趋向于(101)取向,在ZnO晶格显示Ho3+置换. 扫描电子显微镜和能谱仪对薄膜的表面形貌以及化学 相似文献
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利用X射线衍射(XRD)和X射线吸收近边结构(XANES)方法研究了在Si(100)衬底上及600℃温度条件下用分子束外延(MBE)共蒸发方法生长的MnxSi1-x磁性薄膜的结构.由XRD结果表明,只有在高Mn含量(8%和17%)样品中存在着Mn4Si7化合物物相.而XANES结果则显示,对于Mn浓度在0.7%到17%之间的MnxSi1-x样品,其Mn原子的XANES谱表现出了一致的谱线特征.基于多重散射的XANES理论计算进一步表明,只有根据Mn4Si7模型计算出的理论XANES谱才能够很好的重构出MnxSi1-x样品的实验XANES谱.这些研究结果说明在MnxSi1-x样品中,Mn原子主要是以镶嵌式的Mn4Si7化合物纳米晶颗粒存在于Si薄膜介质中,几乎不存在间隙位和替代位的Mn原子.
关键词:
xSi1-x磁性薄膜')" href="#">MnxSi1-x磁性薄膜
分子束外延
XRD
XANES 相似文献
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本文基于磁控溅射方法,功率从160 W增加到240 W,在石英衬底上沉积氧化铪薄膜(HfO2),并对沉积后的薄膜进行退火处理. 利用X射线衍射谱、X射线光电子能谱、紫外-可见-近红外透射谱和椭圆偏振仪对HfO2薄膜进行研究,对比了退火前后HfO2薄膜的光学特性及薄膜结构的变化. 实验结果显示,HfO2薄膜对波长大于200 nm的入射光具有很低的吸收系数. 优化退火温度和时间,可以将沉积后的HfO2薄膜从非晶态转化成多晶态. 退火有助于结晶生成和内应力的增加,同时退火可以优化薄膜的化学计量比,提升薄膜的光学密度及折射率. 对功率在220 W左右沉积的薄膜进行退火,获得的HfO2薄膜具有较高并且稳定的光学折射率(>2)和紫外光透射率,可在紫外波段减反膜系统中得到应用. 相似文献
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利用X 射线衍射(XRD)和X射线吸收精细结构(XAFS)方法研究了磁控共溅射方法制备的MnxGe1-x薄膜样品的结构随掺杂磁性原子Mn含量的变化规律.XRD结果表明,在Mn的含量较低(7.0%)的Mn0.07Ge0.93样品中,只能观察到对应于多晶Ge的XRD衍射峰,而对Mn含量较高(25.0%, 36.0%)的Mn0.25Ge0.75和Mn关键词:
磁控溅射
XRD
XAFS
xGe1-x稀磁半导体薄膜')" href="#">MnxGe1-x稀磁半导体薄膜 相似文献
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Shalendra Kumar S. GautamG.W. Kim Faheem AhmedM.S. Anwar K.H. ChaeH.K. Choi H. ChungB.H. Koo 《Applied Surface Science》2011,257(24):10557-10561
We report structural, magnetic and electronic structure study of Mn doped TiO2 thin films grown using pulsed laser deposition method. The films were characterized using X-ray diffraction (XRD), dc magnetization, X-ray magnetic circular dichroism (XMCD) and near edge X-ray absorption fine structure (NEXAFS) spectroscopy measurements. XRD results indicate that films exhibit single phase nature with rutile structure and exclude the secondary phase related to Mn metal cluster or any oxide phase of Mn. Magnetization studies reveal that both the films (3% and 5% Mn doped TiO2) exhibit room temperature ferromagnetism and saturation magnetization increases with increase in concentration of Mn doping. The spectral features of XMCD at Mn L3,2 edge show that Mn2+ ions contribute to the ferromagnetism. NEXAFS spectra measured at O K edge show a strong hybridization between Mn, Ti 3d and O 2p orbitals. NEXAFS spectra measured at Mn and Ti L3,2 edge show that Mn exist in +2 valence state, whereas, Ti is in +4 state in Mn doped TiO2 films. 相似文献
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R. Bacewicz A. Twaróg T. Wojtowicz X. Liu 《Journal of Physics and Chemistry of Solids》2005,66(11):2004-2007
Local structure of Mn atoms in Ga1−xMnxAs epilayers was studied using the X-ray absorption fine structure (XAFS) at Mn K-edge. X-ray near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) techniques were used. XAFS spectra for different Mn sites has been calculated and compared with the experimental data. Multi-parameter fitting of the EXAFS data indicates that 15-25% of Mn atoms are in interstitial sites in the as grown films. The Mn-As bond length has been found longer than Ga-As bond length in GaAs for both substitutional (MnGa) and interstitial (MnI) sites. 相似文献
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利用磁控溅射和快速热处理的方法制备了Mn,B共掺的多晶硅薄膜(Si0.9654Mn0.0346:B).磁性和结构研究发现薄膜有两个铁磁相.低温铁磁相来源于杂相Mn4Si7,高温铁磁相(居里温度TC~250K)是由Mn原子掺杂进入Si晶格导致.晶化后的薄膜利用射频等离子体增强化学气相沉积系统(PECVD)进行短暂(4min)的氢化处理后发现,薄膜的微结构没有发生变化而饱和磁化强度却随着
关键词:
磁性半导体
硅
氢化 相似文献
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Shuang Qiao Denglu Hou Yanyan Wei Weixia Gao Yuchan Hu Congmian Zhen Guide Tang 《Journal of magnetism and magnetic materials》2009,321(16):2446-2450
MnxGe1−x thin films were prepared by magnetron sputtering with a substrate temperature of 673 K and subsequently annealed at 873 K. The X-ray diffraction (XRD) measurements showed that all samples had a single Ge cubic structure. No films showed clear magnetic domain structure under a magnetic force microscope (MFM). Atom force microscope (AFM) measurements showed that the films had an uniform particle size distribution, and a columnar growth pattern. X-ray photoelectron spectroscopy (XPS) measurements indicated that the valences of both Mn and Ge atoms increase with the Mn concentration. The resistance decreased with increasing temperature, suggesting that the films were typical semiconductors. Magnetic measurements carried out using a Physical Property Measurement System (PPMS) showed that all samples exhibited ferromagnetism at room temperature. There was a small concentration of Mn11Ge8 in the films, but the ferromagnetism was mainly induced by Mn substitution for Ge site. 相似文献
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E Céspedes J. Sánchez-Marcos J. García-López Carlos Prieto 《Journal of magnetism and magnetic materials》2010,322(9-12):1201-1204
The effect of introducing nitrogen and oxygen in the sputtering working gas on the magnetic properties of Mn:ZnO thin films has been investigated. A set of films has been characterized by X-ray diffraction, X-ray absorption near edge structure (XANES) and optical absorption spectroscopy to correlate its magnetic properties with Mn electronic characteristics. Mn2+ substituting Zn2+ in the wurtzite structure has been obtained for the films presenting considerably high saturation magnetization values. The change in the magnetic behaviour seems to be associated with the electronic carrier density in the films. 相似文献
17.
Nanostructured ZnO:Mn thin films have been prepared by sol–gel dip coating method. The content of Mn in the sol was varied from 0 to 12 wt%. The effect of Mn concentration on the optical, structural, and morphological properties of ZnO thin films were studied by using Fourier Transform Infrared (FTIR), UV–visible and photoluminescence (PL) spectroscopy, X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). XRD results showed that the films have hexagonal wurtzite structure at lower content of Mn. The diffraction peaks corresponding to ZnO disappeared and two diffraction peaks of MnO2 and Mn3O4 appeared at the highest value of doping concentration (viz., 12 wt%). SEM results revealed that the surface smoothness of the films improved at higher content of Mn. The optical band gap of the films decreased from 3.89 to 3.15 eV when the Mn concentration increased from 0 to 12 wt%. The PL spectra of the films showed the characteristic peaks linked to band-to-band, green and yellow emissions. Besides, the PL intensity of the samples decreased with increase in Mn concentration. 相似文献
18.
Zhongliang Liu 《Applied Surface Science》2009,255(11):5698-5701
The SiC films were grown by solid source molecular beam epitaxy (SSMBE) on Si (1 1 1) with different amounts of Ge predeposited on Si prior to the epitaxial growth of SiC. The samples were investigated with reflection high energy electron diffraction (RHEED), atomic force microscopy (AFM), and X-ray diffraction (XRD). The results indicate that there is an optimized Ge predeposition amount of 0.2 nm. The optimized Ge predeposition suppress the Si outdiffusion and reduce the formation of voids. For the sample without Ge predeposition, the Si outdiffusion can be observed in RHEED and the results of XRD show the worse quality of SiC film. For the sample with excess amount of Ge predeposition, the excess Ge can increase the roughness of the surface which induces the poor quality of the SiC film. 相似文献
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Yew Hoong Wong V. V. Atuchin V. N. Kruchinin Kuan Yew Cheong 《Applied Physics A: Materials Science & Processing》2014,115(3):1069-1072
To date, the complex evaluation of physical and dispersive optical characteristics of the ZrON/Si film system has yet been reported. Hence, ZrON thin films have been formed on Si(100) substrates through oxidation/nitridation of sputtered metallic Zr in N2O environment at 500, 700, and 900 °C. Physical properties of the deposited films have been characterized by X-ray diffractometry (XRD), Fourier transform infrared (FTIR) spectroscopy, reflection high-energy electron diffraction (RHEED), and spectroscopic ellipsometry (SE). It has been shown that ZrON/Si thin films without optical absorption can be prepared by oxidation/nitridation reaction in N2O environment at 700–900 °C. 相似文献