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1.
D. K. Aswal K. P. Muthe S. C. Karandikar T. Mirza S. K. Gupta S. C. Sabharwal 《Phase Transitions》2013,86(1-3):127-137
Superconducting thin films of Y-Ba-Cu-O have been prepared by 50 Hz ac sputtering on polycrystalline SrTiO3, yttria-stabilized-ZrO2, and MgO substrates. Films deposited on different substrate materials are required to be annealed at different temperatures to induce superconductivity. The optimum annealing temperature for a film depends on the reaction between the film and its substrate material. It appears that a correlation exists between the process of crystallisation and substrate-film reaction. 相似文献
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S. G. Titova L. A. Cherepanova Yu. V. Blinova S. V. Sudareva M. V. Degtyarev E. I. Kuznetsova O. V. Snigirev N. V. Porokhov 《Physics of the Solid State》2013,55(8):1609-1612
The degradation processes of YBa2Cu3O6.77(3) films 600 nm thick deposited on substrates from a textured (100) foil of the Ni-W alloy with the YSZ (Y2O3 + ZrO2) (100 nm) and CeO2 (50 nm) buffer layers at 200°C in air have been investigated. It has been shown that the degradation proceeds in the same manner as in the bulk ceramic materials with the same oxygen content, namely, initially the single-phase material with the orthorhombic structure laminates into the fractions depleted (the main fraction) and enriched with oxygen. After holding for more than 20 h, the oxygen-depleted fraction is first subjected to the structural phase transformation with the transition of the orthorhombic structure into the cubic one, which is associated with the redistribution of barium and yttrium atoms over their sites in the presence of water vapors. 相似文献
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Gi-Seok Heo Yuji Matsumoto In-Gi Gim Jong-Woon Park Kwang-Young Kim Tae-Won Kim 《Solid State Communications》2009,149(41-42):1731-1734
Zn–In–Sn–O (ZITO) films have been grown by rf magnetron cosputtering system from ceramic oxide targets of ZnO and ITO onto glass substrate. X-ray diffraction analysis shows that the microstructure is amorphous below the substrate temperature of 250 °C. The films exhibit sheet resistance as low as 16.7 Ω/□ and optical transparency comparable to grater than that of Sn-doped indium oxide (ITO) films. The work function ranged 5.05–5.19 eV, which is a higher work function compared to ITO (4.7 eV). The fabricated ZITO films are used in fabrication of organic light-emitting diodes (OLEDs). The ZITO anode with the zinc content of 12.5 at.% [Zn/(Zn+In+Sn)] fabricated at 250 °C-based OLED shows lower turn-on voltage and higher current density compared to that of ITO-based control device. 相似文献
5.
J.J. Uhlrich J. Sainio Y. Lei D. Edwards R. Davies M. Bowker S. Shaikhutdinov H.-J. Freund 《Surface science》2011,605(15-16):1550-1555
Mixed Fe–Mo oxides are used in industrial catalytic processes of selective oxidation of methanol to formaldehyde. For better understanding of the structure-reactivity relationships of these catalysts we aim to prepare well-ordered iron–molybdate thin films as model catalysts. Here we have studied Mo deposition onto Fe3O4 (111) thin films produced on Pt(111) as a function of Mo coverage and annealing temperature using LEED, AES, STM and IRAS. At low temperatures, the iron oxide film is covered by Mo = O terminated molybdena nanoparticles. Upon oxidation at elevated temperatures (T > 900 K), Mo species migrate into the film and form new bonds with oxygen in the film. The resulting films maintain the crystal structure of Fe3O4, and the surface undergoes a (√3 × √3)R30° reconstruction. The structure is rationalized in terms of Fe substitution by Mo in the surface layers. 相似文献
6.
Undoped and doped ZnO thin films were prepared by sol–gel method and deposited on tin-doped indium oxides (ITO) substrate using spin coating technique. The effects of Sn and Sb dopants on structural and optical properties were investigated. The starting material was zinc acetate dihydrate, 2-methoxyethanol was used as solvent and monoethanolamine (MEA) as stabilizer. ZnO films were doped with 2% and 7% Sn and Sb concentrations. Optical measurements show an important effect of Sn and Sb dopants on optical band gap. 相似文献
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R. Rössler J.D. Pedarnig D. Bäuerle E.J. Connolly H.W. Zandbergen 《Applied Physics A: Materials Science & Processing》2000,71(3):245-247
Thin films of Bi2Sr2CaCu2O8+δ have been grown on vicinal (001) SrTiO3 substrates by pulsed-laser deposition. Transmission electron microscopy (TEM) and X-ray diffraction reveal well ordered films
with the c axis of the film parallel with the c axis of the substrate for miscut angles up to θS≈15°. TEM also reveals the step-like film morphology due to step-flow growth. The in-plane and out-of-plane resistivities
are independent of film thickness within the range 20–300 nm and agree quite well with Bi2Sr2CaCu2O8+δ single-crystal data.
Received:15 May 2000 / Accepted:17 May 2000 / Published online: 9 August 2000 相似文献
10.
Kai-Huang Chen Ting-Chang Chang Guan-Chang Chang Yung-En Hsu Ying-Chung Chen Hong-Quan Xu 《Applied Physics A: Materials Science & Processing》2010,99(1):291-295
To improve the electrical properties of as-deposited BZ1T9 ferroelectric thin films, the supercritical carbon dioxide fluid
(SCF) process were used by a low temperature treatment. In this study, the BZ1T9 ferroelectric thin films were post-treated
by SCF process which mixed with propyl alcohol and pure H2O. After SCF process treatment, the remnant polarization increased in hysteresis curves, and the passivation of oxygen vacancy
and defect in leakage current density curves were found. Additionally, the improvement qualities of as-deposited BZ1T9 thin
films after SCF process treatment were carried out XPS, C–V, and J–E measurements. 相似文献
11.
《Current Applied Physics》2020,20(9):1041-1048
We report the effect of germanium doping on the active layer of amorphous Zinc–Tin-Oxide (a-ZTO) thin film transistor (TFT). Amorphous thin film samples were prepared by RF magnetron sputtering using single targets composed of Zn2Ge0.05Sn0.95O4 and Zn2SnO4 with variable oxygen contents in the sputtering gases. In comparison with undoped, Ge-doped a-ZTO films exhibited five order of magnitude lower carrier density with a significantly higher Hall-mobility, which might be due to suppressed oxygen vacancies in the a-ZTO lattice since the Ge substituent for the Sn site has relatively higher oxygen affinity. Thus, the bulk and interface trap densities of Ge-doped a-ZTO film were decreased one order of magnitude to 7.047 × 1018 eV−1cm−3 and 3.52 × 1011 eV−1cm−2, respectively. A bottom-gate TFT with the Ge-doped a-ZTO active layer showed considerably improved performance with a reduced SS, positively shifted Vth, and two orders of magnitude increased Ion/Ioff ratio, attributable to the doped Ge ions. 相似文献
12.
Wu Wenwei Fan Yanjin Wu Xuehang Liao Sen Li Shushu 《Journal of Physics and Chemistry of Solids》2009,70(3-4):584-587
The layered nanocrystalline NH4MnPO4·H2O was obtained by grinding MnSO4·H2O and (NH4)3PO4·3H2O in the presence of surfactant PEG-400 via a solid-state reaction at room temperature, maintaining the mixture at room temperature for 12 h, washing the mixture with water, and drying at 60 °C. The resulting NH4MnPO4·H2O and its products of thermal decomposition were characterized using thermogravimetry and differential thermal analyses (TG/DTA), IR, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), UV–vis, and magnetic susceptibility. The data showed that when dried at 60 °C for 5 h, highly crystallized orthorhombic NH4MnPO4·H2O (space group Pmnm(59)) was obtained with an average particle size of 45 nm and an average interlayer distance of 0.8701 nm. On the other hand, monoclinic nanocrystalline Mn2P2O7 with space group C2/m(12) was obtained when the product was calcined at 600 °C for 3 h. Magnetic susceptibility measurements from room temperature to 2.5 K point to ferrimagnetic ordering at TN~17 K. 相似文献
13.
Synthesis of large-scale GaN nanowires by ammoniating Ga2O3 films on Co layer deposited on Si(111) substrates 下载免费PDF全文
A mass of GaN nanowires has been successfully synthesized on Si(111) substrates by magnetron sputtering through ammoniating Ga2O3/Co films at 950℃. X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscope and Fourier transformed infrared spectra are used to characterize the samples. The results demonstrate that the nanowires are of single-crystal GaN with a hexagonal wurtzite structure and possess relatively smooth surfaces. The growth mechanism of GaN nanowires is also discussed. 相似文献
14.
Structural and mechanical properties of Al–C–N films deposited at room temperature by plasma focus device 下载免费PDF全文
The Al–C–N films are deposited on Si substrates by using a dense plasma focus(DPF) device with aluminum fitted central electrode(anode) and by operating the device with CH_4/N_2 gas admixture ratio of 1:1. XRD results verify the crystalline Al N(111) and Al_3CON(110) phase formation of the films deposited using multiple shots. The elemental compositions as well as chemical states of the deposited Al–C–N films are studied using XPS analysis, which affirm Al–N, C–C, and C–N bonding. The FESEM analysis reveals that the deposited films are composed of nanoparticles and nanoparticle agglomerates. The size of the agglomerates increases at a higher number of focus deposition shots for multiple shot depositions. Nanoindentation results reveal the variation in mechanical properties(nanohardness and elastic modulus)of Al–C–N films deposited with multiple shots. The highest values of nanohardness and elastic modulus are found to be about 11 and 185 GPa, respectively, for the film deposited with 30 focus deposition shots. The mechanical properties of the films deposited using multiple shots are related to the Al content and C–N bonding. 相似文献
15.
Optical properties of ZnO thin films on SiO_2 substrates deposited by radio frequency magnetron sputtering 总被引:4,自引:0,他引:4
The optical properties of both the annealed and as-deposited ZnO thin films by radio frequency (RF) magnetron sputtering on SiO2 substrates were studied. In the annealed films, two pronounced well defined exciton absorption peaks for the A and B excitons were obtained in the absorption spectra, a strong free exciton emission without deep-level emissions was observed in the photoluminescence (PL) spectra at room temperature. It was found that annealing the films in oxygen dramatically improved the optical properties and the quality of the films. 相似文献
16.
Growth temperature dependent evolutions of microstructural, optical and magnetic properties of Zn0.75Co0.25O films 下载免费PDF全文
Zn0.75Co0.25O films are fabricated via reactive electron beam evaporation. The influence of growth temperature on the microstructural, optical and magnetic properties of Zn0.75Co0.25O films is investigated by using x-ray diffraction, selected area electron diffraction, field emission scanning electron microscope, high resolution transmitting electron microscope, photoluminescence (PL), field dependent and temperature dependent DC magnetization, and x-ray photoelectron spectroscopy (XPS). It is shown that Zn0.75Co0.25O films grown at low temperatures (250-350℃) are of single-phase wurtzite structure. Films synthesized at 300 or 350℃ reveal room temperature (RT) ferromagnetism (FM), while su for 250℃ fabricated films is found above 56 K. PL and XPS investigations show favour towards the perspective that the O-vacancy induced spin-split impurity band mechanism is responsible for the formation of RT FM of Zn0.75Co0.25O film, while the superparamagnetism of 250℃ fabricated film is attributed to the small size effect of nanoparticles in Zn0.75Co0.25O film. 相似文献
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X.Ju L.Q.Peng 《北京同步辐射装置》2001,(1):3-8
Nanowir array and film of cadmium sulfide were prepared by eletroplating in organic solvent dimethyl sulfoxide with CdCl2 and element sulfur under different temperature and current density.The UV-VIS absorption spectra show that increasing the electroplating temperature is benefit to forming perfect crystallites of energy shift for the lowest sveral excitons is given and compared with th experiment.The photoluminescence spectrum consists of two parts:the first is produced by recombination of the defcets and the second by recombination of excitons. 相似文献
18.
Hongbin Jian Qi Li Dongqi Shi Li Zhang Zhaorong Yang Shixue Dou Xuebin Zhu Yuping Sun 《Physica C: Superconductivity and its Applications》2011,471(23-24):1669-1674
Y1?xHoxBa2Cu3O7?δ (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) thin films were prepared on LaAlO3 (0 0 1) substrates by trifluoroacetate metal organic deposition (TFA-MOD) without change of the processing parameters. The highest Jc was attributed to the sample of Y0.6Ho0.4Ba2Cu3O7?δ thin film, whose critical current density is about 1.6 times as compared to that of YBa2Cu3O7?δ thin film at 77 K and self field. The flux pinning type was not varied with Ho substitution and can be attributed to δl pinning model, which is attributed to the close ionic radius between the Y3+ and Ho3+ ions. The improvement of Jc by Ho substitution without change of the processing parameters will provide an effective route to enhance the Jc of YBCO-based thin films using TFA-MOD method. 相似文献
19.
W. Chen X. H. Pan P. Ding H. H. Zhang S. S. Chen W. Dai J. Y. Huang B. Lu Z. Z. Ye 《Applied Physics A: Materials Science & Processing》2014,116(4):1979-1983
We report the growth and characterization of a series of non-polar Zn1?x Mg x O thin films with different Mg contents, which have been prepared on r-plane sapphire substrates by plasma-assisted molecular beam epitaxy. Structural properties are anisotropic and surfaces of films show stripes running along the c-axis direction. The films exhibit atomically smooth surface with the minimal root mean square surface roughness of 0.36 nm. Non-polar Zn1?x Mg x O thin film is much easier to obtain pure a-plane single crystal orientation when Mg content is high. The quality of the non-polar Zn1?x Mg x O thin films is evidenced by X-ray diffraction (XRD) rocking curves full-width at half-maximum of 1,350 arcsec for the ( \( 11\overline{2} 0 \) ) reflection and 1,760 arcsec for the ( \( 10\overline{1} 1 \) ) reflection, respectively. Room temperature photoluminescence peak shifts monotonously from 3.29 to 3.56 eV as Mg content increases from 0 to 0.13. Alloying with Mg is found to widen the bandgap energy of the ZnO. 相似文献
20.
Dong Zhang Yizhen Bai Fuwen Qin Fuchao Jia Jian Wang Jiming Bian 《Applied Physics A: Materials Science & Processing》2011,102(2):353-358
High-quality GaN films are deposited on freestanding thick diamond films by electron cyclotron resonance plasma enhanced metal
organic chemical vapor deposition (ECR-PEMOCVD). The TMGa flux dependent structural, morphological, and electrical characteristics
of GaN films were investigated by x-ray diffraction analysis (XRD), reflection high-energy electron diffraction (RHEED), atomic
force microscopy (AFM) and Hall effect measurement. The results indicate that it is feasible to deposit GaN films on freestanding
thick diamond films under the proper deposition procedures. The high-quality GaN films with small surface roughness of 4.9 nm
and high c-orientation are successfully achieved at the optimized TMGa flux of 0.5 sccm. The GaN/diamond structure has great
potential for the development of SAW devices with high frequencies and low insertion. 相似文献