共查询到20条相似文献,搜索用时 31 毫秒
1.
A highly oriented FeO thin film was formed from a Fe3O4 thin film containing Fe nanocrystallines by post-annealing at 600°C. Fe3O4 thin films were grown on Si(100) substrates by ion beam sputter deposition under oxygen ambient. The stoichiometry of the iron oxide thin film could be precisely controlled by in situ X-ray photoelectron spectroscopy (XPS). X-ray diffraction (XRD) pattern of the Fe3O4 thin film grown at substrate temperature of 300°C showed a mixed phase of Fe3O4 and Fe nanocrystallines with a preferred orientation (110). However, the mixed phase was converted to a highly oriented FeO(200) phase by post-annealing at 600°C. This could be inverted as a result of Ostwald ripening of the Fe3O4 and Fe nanocrystallines. 相似文献
2.
Epitaxial and polycrystalline barium hexaferrite BaFe12O19 thin films were prepared by metalorganic chemical vapour deposition (MOCVD). Films were grown by a liquid MOCVD technique which aim is to control precisely the precursor vapour pressures. Two kinds of substrates were used: sapphire (001) and silicon thermally oxidized. On Si/SiO2 films are polycrystalline and the magnetization is isotropic. On Al2O3 (001), structural studies reveal the films to be predominantly single phase, well crystallized without annealing procedure and with the c-axis perpendicular to the film plane; epitaxial relationships between the film and the substrate were determined. The magnetic parameters, deduced from vibrating sample magnetometer measurements, show a high dependence of the magnetization with the orientation of the field with respect to the surface of the film. 相似文献
3.
通过低氟MOD法制备了Nb掺杂的YBa2Cu3O7-x(YBCO)薄膜, 掺入的Nb以Ba2YNbO6(BYNO)相存在, 其尺寸大小在20~30 nm之间, 薄膜中BYNO纳米颗粒以外延和随机两种取向共存, 且以随机取向为主。BYNO纳米颗粒的周围出现堆垛层错, 并且BYNO周围的YBCO出现严重的晶格畸变, 这增加了YBCO薄膜内部的微观应变, 且随机BYNO颗粒含量越高, YBCO薄膜内部的微观应变就越大。微观应变增加了薄膜的磁通钉扎能力, 进而提高了薄膜在高磁场下的超导性能。 相似文献
4.
以三元嵌段共聚硅橡胶为基体,Fe73.5Cu1Nb3Si13.5B9软磁粉为应力敏感填充粒子,采用机械共混和精密铸压热成型方法制备出系列粉体含量的Fe73.5Cu1Nb3Si13.5B9软磁粉/硅橡胶接触应力敏感复合材料,重点研究了其交流阻抗、直流电阻、粒子间及粒子与硅橡胶间相互作用程度等性能的逾渗特性。研究表明,该柔性力敏复合材料具有较显著的交流阻抗双逾渗特性。分析发现,“第一逾渗区”内材料的交流阻抗值由粒子的隧道跃迁主导,“第二逾渗区”内材料的交流阻抗大小取决于Fe73.5Cu1Nb3Si13.5B9粒子链间的接触电阻值。 相似文献
5.
Ion-beam assisted deposition of polycrystalline Y2O3 films using e-beam evaporation was investigated. For growth on non-crystalline substrates, low temperature growth yields randomly oriented polycrystalline material. At elevated temperature, surface energy anisotropy yields a (111) uniaxial texture. For film deposition with irradiation from an Ar ion beam, the out-of-plane texture remained (111) in orientation. The incident Ar ion beam induces an in-plane alignment of the Y2O3 films that is relatively broad. A six-fold symmetry in the out-of-plane X-ray diffraction phi-scans was observed for the (111) textured Y2O3 films, indicating a multi-variant in-plane texture and suggesting anisotropic damage along both the (110) and (100) projections. The lack of a sharp, single variant in-plane texture with ion beam irradiation is consistent with the relatively weak bond strength in Y2O3. 相似文献
6.
The contribution of an external magnetic field on the deposition of BaFe12O19 thin film was investigated. For this purpose, two (one with applied field and another without field) thin films of BaFe12O19 were deposited on the C-plane oriented sapphire (Al2O3) substrate employing pulsed laser deposition technique. Crystallographic orientation and texture were determined using an X-ray diffractometer. The magnetic parameters were deduced from a vibrating sample magnetometer (VSM). A spectrometer was used to study the optical properties of the films. The structural results reveal the film to be predominantly single phase with C-plane orientation in both the cases. The film deposited with field, however, has bigger grain size and more perfection in crystallinity. The magnetic parameters show that the film deposited with the field has more remanence magnetization and higher coercive field. The diffuse reflectance of the film deposited with field is much higher due to the increased grain size and roughness. 相似文献
7.
Conductive RuO2 thin films were epitaxially grown on LaAlO3(100) and MgO(100) substrates by metal-organic chemical vapor deposition (MOCVD). The deposited RuO2 films were crack-free, and well adhered to the substrates. The RuO2 film is (200) oriented on LaAlO3 (100) substrates at deposition temperature of 600°C and (110) oriented on MgO(100) substrates at deposition temperature of 350°C and above. The epitaxial growth of RuO2 on MgO and LaAlO3 is demonstrated by strong in-plane orientation of thin films with respect to the major axes of the substrates. The RuO2 films on MgO(100) contain two variants and form an orientation relationship with MgO given by RuO2(110)//MgO(100) and RuO2[001]//MgO[011]. The RuO2 films on LaAlO3(100), on the other hand, contain four variants and form an orientation relationship with LaAlO3 given by RuO2(200)//LaAlO3(100) and RuO2[011]//LaAlO3[011]. Electrical measurements on the RuO2 thin films deposited at 600°C show room-temperature resistivities of 40 and 50 μΩ cm for the films deposited on the MgO and LaAlO3 substrates, respectively. 相似文献
8.
采用浸胶法制备了一系列SiO2-Al2O3/聚酰亚胺(SiO2-Al2O3/PI)五层耐电晕薄膜Am An PAn Am,其中中间层(P)为纯PI薄膜,外层(Am)、次外层(An)分别为SiO2-Al2O3掺杂不同质量分数的纳米SiO2-Al2O3/PI薄膜。采用TEM、FTIR、宽频介电谱仪、电导电流测试仪、耐电晕测试仪、介电强度测试仪和拉伸实验机对五层纳米复合PI耐电晕薄膜的微观结构、介电性能和力学性能进行了表征和测试。结果表明,SiO2-Al2O3/PI复合薄膜掺杂层形成了分布均匀的有机/无机复合结构;SiO2-Al2O3纳米粒子的保护作用是影响复合材料耐电晕性能的主要因素,复合薄膜A32A16PA16A32的耐电晕寿命最大,为23.4 h;外层掺杂量对五层SiO2-Al2O3/PI复合材料的介电强度影响较大,复合薄膜A20A28PA28A20的介电强度最大,为302.3 kV/mm;通过对五层复合结构的设计,可以在兼顾材料力学性能的同时,提高其耐电晕寿命和介电强度。 相似文献
9.
为了研究铁电相BiFeO3对复合薄膜磁性能的影响,在LaNiO3 (LNO)缓冲层的Si (100)衬底上旋涂制备了含有0、6、9、10层等不同厚度BiFeO3的层状CoFe2O4-BiFeO3 (CFO-BFO) 多铁复合薄膜。采用XRD、SEM以及TEM对其结构和形貌进行了表征,采用振动样品磁强计测量磁性,研究了不同厚度BFO对复合薄膜磁性的影响。结果表明: CFO和BFO在异质结构薄膜中共存。缓冲层LNO和铁磁相CFO薄膜具有精细微观结构及明显界面。铁电相BFO的厚度对CFO-BFO复合薄膜的磁性能产生了很大影响。在含有不同层数铁电相BFO的复合薄膜中,含有9层BFO复合薄膜的饱和磁化强度最大,达到了230 emu·cm-3,相比无铁电相BFO的薄膜,饱和磁化强度提高了18.6%。初步讨论认为: 随着铁电相BFO厚度的增加,CFO与BFO之间的应力传导引起了复合薄膜饱和磁化强度的提高。 相似文献
10.
Cusido J. Obradors X. Fontcuberta J. Isalgue A. Canal F. Cortadellas J. Langlet M. Joubert J. 《IEEE transactions on magnetics》1987,23(1):74-76
Thin film iron oxides prepared by a new pyrolisis technique are studied by means of CEM spectroscopy and Faraday rotation measurements. It is shown that Fe3 O4 spinel oxides are obtained when the deposition is performed under Ar atmosphere. These spinel-ferrite films present an important magnetization component perpendicular to the film plane. It is also shown that the Fe3 O4 films are converted to γ-Fe2 O3 by oxidation in air while retaining a uniaxial magnetic anisotropy. We interpret this induced magnetic anisotropy as arising from a magnetoelastic coupling with the substrate. Faraday rotation hysteresis loops confirm the existence of a strong induced uniaxial magnetic anisotropy in these films. 相似文献
11.
A continuous and highly biaxially textured CdTe film was grown by metal organic chemical vapor deposition on an amorphous substrate using biaxial CaF2 nanorods as a buffer layer. The interface between the CdTe film and CaF2 nanorods and the morphology of the CdTe film were studied by transmission electron microscopy (TEM) and scanning electron microscopy. Both the TEM and X-ray pole figure analysis clearly reveal that the crystalline orientation of the continuous CdTe film followed the {111}<121> biaxial texture of the CaF2 nanorods. A high density of twin faults was observed in the CdTe film. Furthermore, the near surface texture of the CdTe thin film was investigated by reflection high-energy electron diffraction (RHEED) and RHEED surface pole figure analysis. Twinning was also observed from the RHEED surface pole figure analysis. 相似文献
12.
Bismuth titanate (Bi4Ti3O12) thin films with a high c-axis orientation up to 99% were prepared on (100)-oriented silicon wafers by r.f. planar magnetron sputtering using a Bi2TiO5 ceramic target at a substrate temperature of 600 °C. From the Auger electron spectroscopy depth profile of the film, there is no evidence of interdiffusion of a specific element between the film and the substrate. Relative dielectric constant of these films depends on film thickness. The behavior was explained assuming a low-dielectric-constant interface layer. Using this assumption, the relative dielectric constant of Bi4Ti3O12 film was estimated to be approximately 140. This value is close to that along the c axis in a bulk form. The remanent polarization and the coercive field were 0.8 μC cm−2 and 20 kV cm−1, respectively. 相似文献
13.
Chunling Yu Jin Zhai Zhen Li Meixiang Wan Mingyuan Gao Lei Jiang 《Thin solid films》2008,516(15):5107-5110
4-dodecylbenzenesulfonic acid-doped polyaniline/Fe3O4 composite honeycomb structure film is obtained by water-assisted self-assembly method. The morphologies of this honeycomb structure film were studied by transmission electron microscopic and atomic force microscropy, while the Fourier transform infrared spectra were obtained to illustrate its composition. This as-prepared film with conducting polymers and magnetic inorganic compounds is proved to show superparamagnetic property. Fabrication of 3D ordered macro-porous structures with conducting polymers and magnetic inorganic compounds should lead to applications in electronic-magnetic materials. 相似文献
14.
La0.5Sr0.5CoO3−δ (LSCO) thin films were deposited on yttria stabilized zirconia (YSZ) substrates by pulsed laser deposition (PLD) for application to thin film solid oxide fuel cell electrodes. During the deposition, the substrate temperature was varied from 450 to 750°C, and the oxygen pressure in the chamber was varied from 80 to 310 mTorr. Films deposited at 650°C and an oxygen background pressure of 150 mTorr were mostly (100) oriented. Deposition at higher temperatures or under lower oxygen pressures lead to mostly (110) oriented films. Films with low electrical resistivity of 10−3 Ω·cm were obtained. 相似文献
15.
采用磁控溅射工艺,以Fe3O4磁性导体作为基底材料在其表面制得Nd Co Cr合金薄膜,分析了加入不同比例Co的情况下制得的Nd-Co非晶薄膜垂直磁各向异性(PMA)性能及其磁畴特征,同时对退火态薄膜组织相成分和磁性进行研究。结果表明:本实验制得了具有非晶形态的薄膜结构,当薄膜内的Co含量增加后,形成了强度更高的Fe3O4衍射峰。当Co含量逐渐增大后,Ms发生了不断增强。初始薄膜Keff表现为随Co含量增大而提高。Co含量为4%试样MFM图像上形成了明暗相间条纹。通过MFM方法测试得到的ΔΦr曲线表现为与Ku曲线形状具有明显相似性,都在Co含量为6%位置处达到最大值。各退火态试样中都形成了Nd4Co3、Nd2Co17、Nd Co Cr2。当薄膜内析出Nd Co Cr5与Nd2Co7纳米晶后,获得了更大矫顽力,当Co含量大于4%时,退火态薄膜形成了较低的矫顽力。 相似文献
16.
H.B. Kim M.H. Cho S.W. Whangbo C.N. Whang S.C. Choi W.K. Choi J.H. Song S.O. Kim 《Thin solid films》1998,320(2):169-172
The heteroepitaxially grown yttrium oxide layer by an ionized cluster beam (ICB) on a Si(100) substrate was investigated by Rutherford backscattering spectrometry (RBS)/channeling. The channeling minimum value (χmin) of the Y2O3 layer on Si(100) is 0.28, and this is the smallest value among those reported. From the channeling polar plots, it is found that Y2O3 film grown on Si(100) oriented with (110) direction and has a double domain structure. The 110 axis of Y2O3 layer is exactly parallel to the 100 axis of the Si substrate. It is also observed that the interface region of Y2O3 film has more crystalline defects than the surface region. 相似文献
17.
The crystal orientation of silver films evaporated onto glass in a vacuum of better than 1.33 × 10−3 Pa was studied as a function of the film thickness in the range 0.1–10 μm by means of the X-ray texture goniometer technique. When the substrate was at room temperature and the deposition rate was high (200 and 100 nm s−1), the 111 orientation was prominent at small film thicknesses. Further film growth led to a rapid increase in the 100 orientation, which became predominant. Elevation of the substrate temperature at the same deposition rates resulted in a decrease in the number of crystallites oriented along the 100 axis, and at temperatures above 473 K the 111 orientation was dominant over the whole thickness range investigated. At a comparatively low deposition rate of 5 nm s−1 at both room temperature and 573 K the crystallites were oriented with their (111) planes parallel to the substrate independent of the film thickness. 相似文献
18.
Transparent and crack-free Bi2Ti2O7 thin films with strong (111) orientation were successfully prepared on n-Si(100) by chemical solution deposition (CSD) using bismuth nitrate and titanium butoxide as starting materials. The structural properties were studied by X-ray diffraction. The dielectric constant at 100 kHz at room temperature was 118 and loss factor was 0.074, for a 0.4-μm-thick film annealed at 500°C for 30 min. The leakage current density was 4.06×10−7 A/cm2 at an applied voltage of 15 V. 相似文献
19.
通过高能球磨技术制备了Fe78Si13B9磁性非晶合金粉体,采用XRD和DSC分析了Fe78Si13B9非晶合金粉体的相组成、玻璃转变温度Tg、开始晶化温度 Tx 和晶化峰温度Tp;利用放电等离子烧结(SPS)技术在不同烧结温度下制备了块体磁性非晶纳米晶合金试样,利用XRD、SEM、Gleeble3500、VSM等分析了不同烧结温度下烧结块体试样的相转变特性、微观形貌、力学性能和磁学性能。结果表明,在500 MPa的烧结压力下,随着烧结温度的升高,烧结试样中的非晶相开始逐渐晶化,烧结试样的致密度、抗压强度、微观硬度、饱和磁化强度均显著提高;在500 MPa的烧结压力和823.15 K的烧结温度下,获得了密度为6.6 g/cm3,抗压强度为1500 MPa,饱和磁化强度为1.3864 T的非晶纳米晶磁性材料。 相似文献
20.
《IEEE transactions on magnetics》2000,36(2):521-527
Recording design alternatives are analyzed for 100 1 Gbit/in2 vertical and horizontal patterned media, written at 1 Gbit/s with one and two pole heads. Bit write fields, disturb fields, and switching speeds are calculated as part of a system analysis of the theoretical potential of patterned media to address possible physics limits for conventional “featureless” continuous film media (these include thermal decay, nonlinear transition shift and transition noise, and high writer pole Ms requirements near the limit of known materials). The patterned media “bits” are assumed oriented vertically or horizontally by crystalline anisotropy, and smaller than 100 nm to allow single-domain, 1/2 ns switching. MsHc V/kT>500, implying thermal stability including media demagnetization and write head remanent fields, are nearly an order of magnitude areal density extensibility beyond 100 Gbit/in2 with present-day head/media magnetic requirements 相似文献