共查询到20条相似文献,搜索用时 437 毫秒
1.
V. S. Sypchenko N. N. Nikitenkov Yu. I. Tyurin I. V. Dushkin E. S. Kiseleva Yu. N. Yur’ev 《Bulletin of the Russian Academy of Sciences: Physics》2014,78(6):540-543
The penetration of hydrogen through protective layers of aluminum oxide fixed on the surface of nanocrystalline (NC) titanium is studied. A film 400 nm thick is prepared by the magnetron sputtering. Radiation- and thermally-induced gas release are employed. It is found that the Al x O1?x film prevents the release of hydrogen from a sample under both radiation and thermal effects. The temperature of hydrogen extraction from metal hydride accumulators can be reduced by 200–250°C, provided that heating is performed under conditions of surface irradiation by electrons with energies of ~30 keV and current densities of 2 to 3 μA cm?2. 相似文献
2.
采用射频磁控溅射技术在Pt/Ti/SiO2/Si(100)衬底上生长了掺镧钛酸铅(PLT)铁电薄膜.用X射线衍射技术(XRD)研究了PLT薄膜结晶性能,结果表明PLT薄膜为 (111)择优取向钙钛矿相织构.使用原子力显微镜(AFM)和压电响应力显微镜(PFM) 分别观察了PLT薄膜的表面形貌和对应区域的电畴结构.PFM观察显示PLT薄膜中存在90°纳米带状畴,电畴的极化为首尾相接的低能量的排列方式,带状畴的宽度为20—60nm.研究了PLT10铁电薄膜的制备条件与性能之间的关系.发现在优化条件下制备的PLT10铁电薄膜的介电常数εr为365、介电损耗tgδ为0.02,热释电系数γ为2.18×10-8C·(cm2·K)-1,可以满足制备非制冷红外探测器的需要.
关键词:
PLT薄膜
电畴
PFM
极化 相似文献
3.
C.K. Lee 《Applied Surface Science》2008,254(13):4111-4117
A diamond film was deposited on silicon substrate using hot filament chemical vapor deposition (HFCVD), and H2 and O2 gases were added to the deposition process for comparison. This work evaluates how adding H2 and O2 affects the corrosion and wear-corrosion resistance characteristics of diamond films deposited on silicon substrate. The type of atomic bonding, structure, and surface morphologies of various diamond films were analyzed by Raman spectrometry, X-ray diffraction (XRD) and atomic force microscopy (AFM). Additionally, the mechanical characteristics of diamond films were studied using a precision nano-indentation test instrument. The corrosion and wear-corrosion resistance of diamond films were studied in 1 M H2SO4 + 1 M NaCl solution by electrochemical polarization. The experimental results show that the diamond film with added H2 had a denser surface and a more obvious diamond phase with sp3 bonding than the as-deposited HFCVD diamond film, effectively increasing the hardness, improving the surface structure and thereby improving corrosion and wear-corrosion resistance properties. However, the diamond film with added O2 had more sp2 and fewer sp3 bonds than the as-deposited HFCVD diamond film, corresponding to reduced corrosion and wear-corrosion resistance. 相似文献
4.
Tin oxide (SnO2) thin films have been grown on glass substrates using atmospheric pressure chemical vapour deposition (APCVD) method. During
the deposition, the substrate temperature was kept at 400°C–500°C. The structural properties, surface morphology and chemical
composition of the deposited film were studied by X-ray diffraction (XRD), scanning electron microscope (SEM) and Rutherford
back scattering (RBS) spectrum. XRD pattern showed that the preferred orientation was (110) having tetragonal structure. The
optical properties of the films were studied by measuring the transmittance, absorbance and reflectance spectra between λ = 254 nm to 1400 nm and the optical constants were calculated. Typical SnO2 film transmits ∼ 94% of visible light. The electrical properties of the films were studied using four-probe method and Hall-voltage
measurement experiment. The films showed room temperature conductivity in the range 1.08 × 102 to 1.69 × 102 Ω−1cm−1. 相似文献
5.
V. V. Brazhkin A. G. Lyapin R. N. Voloshin S. V. Popova Yu. A. Klyuev A. M. Naletov S. C. Bayliss A. V. Sapelkin 《JETP Letters》1999,69(11):869-875
The results of an investigation of the transformation of C60 fullerite to diamond under pressure through intermediate three-dimensionally polymerized and amorphous phases are reported.
It is found that treatment of fullerite C60 at pressures 12–14 GPa and temperatures ∼1400°C produces a nanocrystalline graphite-diamond composite with a concentration
of the diamond component exceeding 50%. At lower temperatures (700–1200°C) nanocomposites consisting of diamondlike (sp
3) and graphitic (sp
2) amorphous phases are formed. The nanocomposites obtained have extremely high mechanical characteristics: hardness comparable
to that of best diamond single crystals and fracture resistance two times greater than that of diamond. Mechanisms leading
to the transformation of C60 fullerite into diamond-based nanocomposites and the reasons for the high mechanical characteristics of these nanocomposites
are discussed.
Pis’ma Zh. éksp. Teor. Fiz. 69, No. 11, 822–827 (10 June 1999) 相似文献
6.
M. C. Kao H. Z. Chen S. L. Young 《Applied Physics A: Materials Science & Processing》2010,98(3):595-599
The preferred (002) orientation zinc oxide (ZnO) nanocrystalline thin films have been deposited on FTO-coated glass substrates
by sol–gel spin-coating technology and rapid thermal annealing for use in dye-sensitized solar cells (DSSC). The effects of
preannealing temperature (100 and 300°C) on the microstructure, morphology and optical properties of ZnO thin films were studied.
The ZnO thin films were characterized by X-ray diffraction (XRD), scanning electron microscopic (SEM) and Brunauer–Emmett–Teller
(BET) analysis. The photoelectric performance of DSSC was studied by I–V curve and the incident photon-to-current conversion efficiency (IPCE), respectively. From the results, the intensities of
(002) peaks of ZnO thin films increases with increasing preannealing temperature from 100°C to 300°C. The increase in pore
size and surface area of ZnO films crystallized at the increased preannealing temperature contributed to the improvement on
the absorption of N3 dye onto the films, the short-circuit photocurrent (J
sc) and open-circuit voltage (V
oc) of DSSC. The higher efficiency (η) of 2.5% with J
sc and V
oc of 8.2 mA/cm2 and 0.64 V, respectively, was obtained by the ZnO film preannealed at 300°C. 相似文献
7.
8.
《Solid State Ionics》2006,177(3-4):389-393
Dense BaCe0.8Sm0.2O2.90 (BCSO) thin films were successfully fabricated on porous NiO–BCSO substrates by dry pressing process. As characterized by scanning electron microscope, the BCSO films were about 50 μm. With Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) as cathodes, single cells were tested at 600 and 700 °C with humidified (3% HB2O) hydrogen as fuel and oxygen as oxidant. The open circuit voltage of 1.049 V at 600 °C and 1.032 V at 700 °C were achieved, indicating negligible gas permeation through the BCSO thin films. Maximum power densities of 132 and 340 mW/cm2 were obtained at 600 and 700 °C, respectively. The impedance measurements at open circuit conditions showed that there were two rate-limiting processes for the electrode reactions and that the cell performances were essentially determined by the electrode polarization resistances at temperature below 650 °C, which implied that it was essential to reduce the electrode polarization by developing novel electrode materials to improve the performance of ITSOFC based on BCSO electrolyte. Conductivities of BCSO under the cell operating circumstances were obtained as 0.00416, 0.00662 and 0.00938 Scm− 1 at 500, 600 and 700 °C, respectively. The activation energy of BCSO conductivity was calculated as 29.5 and 43.8 kJ/mol for the temperature range of 550–700 °C and of 400–550 °C, respectively. Endurance test was firstly carried out with 75 μm BCSO electrolyte at 650 °C at the operating voltage of 0.7 V and current density about 0.12 A/cm2. Both voltage and current density remained stable for 1000 min. 相似文献
9.
10.
R.A. Gunasekaran J.D. Pedarnig M. Dinescu 《Applied Physics A: Materials Science & Processing》1999,69(6):621-624
A parametric study of the growth of La0.5Sr0.5CoO3 (LSCO) thin films on (100) MgO substrates by pulsed-laser deposition (PLD) is reported. Films are grown under a wide range
of substrate temperature (450–800 °C), oxygen pressure (0.1–0.9 mbar), and incident laser fluence (0.8–2.6 J/cm2). The optimum ranges of temperature, oxygen pressure, and laser fluence to produce c-axis oriented films with smooth surface morphology and high metallic conductivity are identified. Films deposited at low
temperature (500 °C) and post-annealed in situ at higher temperatures (600–800 °C) are also investigated with respect to their
structure, surface morphology, and electrical conductivity.
Received: 20 November 1998 / Accepted: 6 July 1999 / Published online: 21 October 1999 相似文献
11.
A. Tsukada K. E. Luna R. H. Hammond M. R. Beasley J. F. Zhao S. H. Risbud 《Applied Physics A: Materials Science & Processing》2011,104(1):311-318
We report the effects of growth conditions on the superconducting properties of FeSe films epitaxially grown on LaAlO3 substrates by pulsed laser deposition (PLD). Customary materials characterization techniques [X-ray diffraction (XRD), in-situ
X-ray photoelectron spectroscopy (XPS), in-situ ultra-violet photoelectron spectroscopy (UPS), and scanning electron microscopy
(SEM)] revealed the films had a c-axis oriented tetragonal structure with lattice constants dependent on the growth temperature (varied from 100 to 600°C).
The standard four-point probe method was used to measure the resistivity and superconducting transitions. Films grown at 400–550°C
showed a clear superconducting onset but no zero resistance down to 2 K. The highest superconducting onset temperature (TconsetT_{\mathrm{c}}^{\mathrm{onset}}) of 8 K was observed in films grown at 500°C and the onset temperature was clearly correlated to the ratio of the lattice
constants (c/a). As the thickness of the FeSe films increased from 27 nm to 480 nm, TconsetT_{\mathrm{c}}^{\mathrm{onset}} also increased as the strain in the system was relaxed. 相似文献
12.
This report describes the amino functionalisation of the surface of plasma enhanced chemically vapour deposited silica films (PECVD-SiO2), which were coated onto titanium substrates. Amino groups were linked to PECVD-SiO2 via 3-aminpropyl triethoxysilane (APTES). We showed that the APTES functionalised PECVD-SiO2 surfaces contained a high packing density of amino groups (67-92 NH2 groups per nm2), indicative of a multilayered and highly cross-linked APTES film. 65-66% of the original surface concentration of APTES was retained on the PECVD-SiO2 surface after incubation under physiological conditions, indicating that APTES films are relatively stable on PECVD-SiO2 in these environments. The stability of the amino groups obtained on PECVD-SiO2 in this study is much higher compared to other hydroxyl-bearing materials, such as titanium. Therefore, PECVD-SiO2 films may find use as functional biomaterial coatings and as intermediate adhesion layers in silanisation processes. 相似文献
13.
Feoktistov N. A. Sakharov V. I. Serenkov I. T. Tolmachev V. A. Korkin I. V. Aleksenskii A. E. Vul’ A. Ya. Golubev V. G. 《Technical Physics》2011,56(5):718-724
The aerosol deposition of detonation nanodiamonds (DNDs) on a silicon substrate is comprehensively studied, and the possibility
of subsequent growth of nanocrystalline diamond films and isolated particles on substrates coated with DNDs is demonstrated.
It is shown that a change in the deposition time and the weight concentration of DNDs in a suspension in the range 0.001–1%
results in a change in the shape of DND agglomerates and their number per unit substrate surface area N
s
from 108 to 1011 cm−2. Submicron isolated diamond particles are grown on a substrate coated with DND agglomerates at N
s
≈ 108 cm−2 using microwave plasma-enhanced chemical vapor deposition. At N
s
≈ 1010 cm−2, thin (∼100 nm) nanodiamond films with a root-mean-square surface roughness less than 15 nm are grown. 相似文献
14.
N. V. Vostokov S. V. Gaponov B. A. Gribkov Yu. N. Drozdov D. V. Masterov V. L. Mironov Yu. N. Nozdrin E. E. Pestov 《Physics of the Solid State》2003,45(11):2025-2030
The surface morphology and superconducting properties of YBaCuO epitaxial films prepared through magnetron sputtering from targets of different cation composition were systematically studied. It was shown that small changes in the growth conditions and relatively small variations in the cation composition of the condensate noticeably affect the surface morphology of the films and their structural and superconducting properties, thus offering an efficient way of controlling the YBCO film parameters. It was found that the 90° off-axis configuration of the magnetron sputtering system permits realization of growth conditions in which the grown films do not contain CuO precipitates and exhibit good superconducting properties (Tc≥88 K, jc(77 K)≥4×106 A/cm2). 相似文献
15.
Surface phenomena which occur in the course of titanium hydride TiHx formation during the H2 interaction with thin Ti films deposited in situ under UHV conditions were studied by means of surface potential and pressure measurements. The elementary steps of this process were distinguished and described. 相似文献
16.
We have demonstrated an approach for the electrostatic assembly of CdTe quantum dots (QDs) with different charged ligands as sensitizers, achieving high coverage and good dispersion in TiO2 porous films. The CdTe QD-sensitized TiO2 porous films were subjected to thermal annealing in a high vacuum chamber to remove the ligand linker, resulting in the formation of direct heterojunctions between the bare CdTe QDs and TiO2 for a favorable charge transfer. The as-received CdTe QD-sensitized TiO2 porous films were employed as photoanodes for quantum dot-sensitized solar cells (QSSCs), and the photocurrent density reached as high as 4.69 mA/cm2 under a standard illumination condition of simulated AM 1.5G (100 mW/cm2). 相似文献
17.
高电荷态离子$lt;sup$gt;126$lt;/sup$gt;Xe$lt;sup$gt;$lt;i$gt;q$lt;/i$gt;+$lt;/sup$gt;引起GaN表面形貌变化研究 下载免费PDF全文
用不同电荷态的126Xeq+离子(9≤q≤30)在室温下轰击GaN晶体表面,经原子力显微镜分析表明,当q>18,辐照区域由隆起转为显著的刻蚀.被轰击后的GaN晶体表面形貌主要取决于入射离子的电荷态.同时,样品表面形貌还与入射离子的剂量和入射角有关;在实验参数范围,与入射离子的初动能没有明显关系(180 keV≤Ek≤600 keV).当入射离子的电荷态q=18,与样品表面法线成60°角倾斜入射和垂直表面入射时,样品的表面几乎没有变化,只是倾斜入射后有很微小的隆起;当q<18时,样品表面膨胀隆起,粗糙度增强,倾斜入射时表面隆起比垂直入射时更明显,而且都有清晰的峰状分界区;当q>18时,样品表面被蚀刻呈凹陷状,有明显的齿状刻痕,且侵蚀深度与离子剂量近似呈线性关系,倾斜入射时的刻蚀深度大于垂直入射时的刻蚀深度.
关键词:
高电荷态离子
GaN晶体
原子力显微镜
表面形貌 相似文献
18.
在不同实验条件下,用微波等离子体化学气相沉积(MPCVD)技术在Si基体上制备了S掺杂和B-S共掺杂CVD金刚石薄膜,利用X射线衍射仪和拉曼光谱仪研究掺杂对CVD金刚石薄膜的应力影响.研究结果发现,随着S掺杂浓度的增加,薄膜中sp2杂化碳含量和缺陷增多,CVD金刚石薄膜压应力增加;小尺寸的B原子与大尺寸的S原子共掺杂时,微量B的加入改变了CVD金刚石薄膜的应力状态,共掺杂形成B-S复合体进入金刚石晶体后降低金刚石晶体的晶格畸变程度,减少S原子在晶界上偏聚数量和晶体中非金刚石结构相含量,降低由于杂质、缺陷及sp2杂化碳含量产生的晶格畸变和薄膜压应力,提高晶格完整性.
关键词:
金刚石薄膜
掺杂
应力 相似文献
19.
M.G. Donato G. Faggio M. Marinelli G. Messina E. Milani A. Paoletti S. Santangelo A. Tucciarone G. Verona Rinati 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,20(1):133-139
High quality synthetic diamonds were grown on single-crystal silicon by microwave plasma enhanced chemical vapour deposition
(CVD). A careful optimisation of both the experimental setup and the growth parameters was necessary before that the achievement
of the best results was made possible. The films were deposited using a CH4-H2 gas mixture at methane concentrations variable in the range 0.6-2.2%, while the substrate temperature was fixed at 750 °C. Raman spectroscopy and photoluminescence (PL) were utilised to monitor the quality of the deposited films and to study
the spatial distribution of defects, respectively. Micro-Raman analysis shows that linewidths of the diamond peak lower than
2.4 cm-1 can be easily measured at the growth surface, indicating that the crystalline quality of individual grains is comparable
to that of the best natural diamonds. The excellent phase purity of the diamond microcrystals at the growth surface is witnessed
by the complete absence of any non-diamond carbon feature and by a very weak luminescence background in the 1.6-2.4 eV spectral
range. A worsening of the quality of the diamond particles is found moving from the growth surface towards the film-substrate
interface. A photoluminescence feature at about 1.68 eV, commonly associated to Si impurities, is distinctly observed as the
exciting laser beam is focused close to the interface. A progressive degradation of the global quality of the films is found
with increasing methane concentration in the gas mixture, as witnessed by an increased PL background in the films grown at
higher methane concentrations.
Received 24 November 2000 相似文献
20.
In this work we study the interaction of water molecules with deuterated and bare polycrystalline diamond surfaces upon exposure to water vapor by X-ray photoelectron spectroscopy (XPS) and high resolution electron energy loss spectroscopy (HR-EELS). To distinguish the molecular origin of hydrogen bonds (i.e. C–H, O–H, C–O–H, etc.) formed on the diamond surface upon interaction with the water molecules, deuterated and hydrogenated gases were used in our experiments. Diamond films were deposited from a deuterated gas mixture to induce C(di)-D surface terminations. Water adsorption on bare diamond surface gives rise to the appearance of well defined and pronounced C–H and C–OH vibrational HR-EELS peaks and an intense O (1s) XPS peak. These chemically adsorbed water fragments survive 300 °C anneal temperature under ultra-high vacuum conditions. Annealing at 600 °C of the water exposed bare diamond surface results in disappearance of the C–OH vibrational modes alongside with a pronounced reduction of the C–H vibrational modes, whilst only upon annealing to ~ 800 °C the O (1s) XPS peak decreased substantially in intensity. We associate these effects with dissociative adsorption of the water molecules on the bare diamond surfaces.Water exposure onto a deuterated surface, on the other hand, does not result in the appearance of the C–OH vibrational peaks but only to an increase of the C–H vibrational HR-EELS mode along side with the appearance of a weaker XPS O (1) peak, as compared to the same experiment, performed on the bare surface. 300 °C anneal significantly diminishes surface oxygen concentration, as monitored by XPS. We associate these results with H2O decomposition reactions and also with molecular adsorption on deuterated diamond surfaces. Annealing of the water exposed deuterated diamond surface, results in a pronounced decrease and disappearance of the O (1s) XPS peak at a temperature of ~ 800 °C. 相似文献