共查询到20条相似文献,搜索用时 46 毫秒
1.
I. V. Bodnar’ V. F. Gremenok Yu. A. Nikolaev V. Yu. Rud’ Yu. V. Rud’ E. I. Terukov 《Technical Physics Letters》2007,33(2):111-113
Polycrystalline n-type CuIn3Se5 and CuIn5Se8 films with thicknesses from 0.4 to 1 μm have been grown by pulsed laser ablation of bulk p-CuIn3Se5 and n-CuIn5Se8 crystals in vacuum. The temperature dependences of the resistivities of these crystals are determined by deep donor levels with energies E D ? 0.2–0.3 eV. Photosensitive thin-film structures based on these films have been created for the first time and their photosensitivity spectra have been measured. The possibility of using thin CuIn3Se5 and CuIn5Se8 films in broadband photoconverters is demonstrated. 相似文献
2.
A. N. Georgobiani B. G. Tagiev O. B. Tagiev Kh. B. Ganbarova U. F. Kasumov 《Inorganic Materials》2010,46(10):1054-1056
We have measured the photoluminescence and Raman spectra of (Ga2S3)0.95(Sm2O3)0.05 crystals and identified the mechanism of the energy transfer from the host to the rare-earth ion and the vibrational modes
of the constituent atoms. 相似文献
3.
Qingyu Xu Zheng Wen Jinlong Gao Xiao Liu Di Wu Shaolong Tang Bin Yang 《Journal of Superconductivity and Novel Magnetism》2011,24(5):1497-1500
(Bi0.9Ba0.1)(Fe0.95Mn0.05)O3 films were prepared on LaNiO3-coated surface oxidized Si substrates. XRD and Raman measurements confirm that the (Bi0.9Ba0.1)(Fe0.95Mn0.05)O3 film has pure R3c structure. Clear ferromagnetism with saturated magnetization of about 25 emu/cm3 has been observed at room temperature. The ferroelectric properties of the (Bi0.9Ba0.1)(Fe0.95Mn0.05)O3 film was confirmed by the observation of the ferroelectric domains and the converse piezoelectric coefficient d
33 versus applied voltage hysteresis loops by piezoelectric force microscopy (PFM). The observation of ferromagnetism and ferroelectricity
in (Bi0.9Ba0.1)(Fe0.95Mn0.05)O3 films indicates the potential multiferroic applications. 相似文献
4.
A. A. Amirov I. K. Kamilov A. B. Batdalov I. A. Verbenko O. N. Razumovskaya L. A. Reznichenko L. A. Shilkina 《Technical Physics Letters》2008,34(9):760-762
The technology of ceramic BiFeO3, Bi0.95Nd0.05FeO3, and Bi0.95La0.05FeO3 multiferroics is described. The room-temperature magnetization, magnetoelectric (ME), and magnetodielectric (MDE) effects
in these compounds have been studied. It is established that even a small fraction (x = 0.05) of rare-earth additives (La, Nd) to bismuth ferrite not only enhance its magnetic properties, but also significantly
influence the ME and MDE effects. The dependence of the ME effect on the frequency of modulation of the alternating magnetic
field in Bi0.95Nd0.05FeO3, and Bi0.95La0.05FeO3 is more pronounced than in pure BiFeO3. 相似文献
5.
A. A. Dakhel 《Journal of Materials Science》2012,47(7):3034-3039
A layer-by-layer deposition technique of Ga2O3 and WO3 by vacuum evaporation method on glass and silicon substrates and subsequent annealing in oxygen atmosphere to form W-doped
Ga2O3 (or Ga2O3:W) films was attempted here. The W doping level was measured by the energy dispersive X-ray fluorescence radiographic analysis.
The crystalline structure of Ga2O3:W films was determined by the X-ray diffraction method. Experimental data indicate that W6+ ions doped in host Ga2O3 forming solid solutions (SS), in which the molar ratio (r) of W to Ga is 9.6, 13.4, 18.2, 22.7 and 30.4%. All the prepared SS have the known β-Ga2O3 crystalline structure. This doping controls the optical and electrical properties of the host Ga2O3. The optical properties of the prepared Ga2O3:W films were studied by UV–VIS–NIR absorption spectroscopy method from which the bandgap was determined. In general, it was
found that the prepared Ga2O3:W films are wide-bandgap semiconductors with bandgap 4.69–4.47 eV and have dielectric properties. The optical sensitivity
of the capacitance, dissipation factor and ac-conductance of the Ga2O3:W films grown on Si was studied as a function of W-doping level. It was observed that the prepared Ga2O3:W film of r = 22.7% has the highest photosensitivity amongst the other samples. 相似文献
6.
V. V. Randoshkin N. V. Vasil’eva V. N. Kolobanov V. V. Mikhailin N. N. Petrovnin D. A. Spasskii N. N. Sysoev 《Inorganic Materials》2009,45(4):418-422
Single-crystal gadolinium gallium garnet films have been grown by liquid-phase epitaxy on (111) Gd3Ga5O12 substrates from supercooled Bi2O3-B2O3 fluxed melts at different Gd2O3 concentrations. The luminescence spectra of the films have been measured at 10 and 300 K under unmonochromatized synchrotron X-ray excitation and selective UV synchrotron excitation. The Bi3+ luminescence is discussed. 相似文献
7.
Chalcogenide amorphous thin films of the modification (As2S3)0.95Cu0.05 were prepared using a thermal evaporation technique. The optical properties of the resultant films were investigated based on the transmittance spectra in the photon energy range 1.6–2.82 eV. Thicknesses of the films under study were determined using the envelope technique based on the transmittance spectra. The optical measurements were carried out over the conditional temperature extending from 77 to 300 K. The results of the mentioned measurements are conductive tools in investigating the electronic structures of the Chalcogenide Glasses, however the analysis of the experimental results provide information about the optical gap width and elucidate the broadness of the band tail that may disturb the band gap edges. Moreover, the single-effective oscillator was implemented in calculating both the oscillation and dispersion energies of the films under investigation. The static refractive index and the static dielectric constant were also determined for these films. 相似文献
8.
La3Ga5SiO14 (LGS) thin films have been grown by r.f. sputtering at 600 °C on (200)-textured MgO buffer layers deposited also by r.f.
sputtering on Si substrates. The evolution of crystalline phases in the thin films as a function of time was examined by X-ray
diffraction and scanning electron microscopy before and after annealing in air for various times. The morphology of the crystals
formed and their formation mechanism were discussed. 相似文献
9.
Yuguo Yang Bing Liu Yuanyuan Zhang Xianshun Lv Lei Wei Jianhua Xu Huadi Zhang Xuping Wang Cong Zhang Jing Li 《Journal of Materials Science: Materials in Electronics》2018,29(20):17154-17159
Mg2+/Ga3+ doped Y3Al5O12:Ce3+ phosphors were synthesized through a solid state reaction. The phase and luminescent of the synthesized phosphors were investigated. For Ga3+ codoped Y2.96Ce0.04Al(5?x)GaxO12 phosphors, the emission intensity increases with the increase of Ga3+ concentration up to Y2.96Ce0.04Al4.80Ga0.20O12 and then decreases with a further increase of Ga3+ concentration, but the emission peak shifts to shorter wavelength continuously in the Ga3+ doping concentration range of 0.05–0.25. For Mg2+/Ga3+ codoped Y2.96Ce0.04Al(4.8?y)Ga0.20MgyO12 phosphors, the emission intensity decreases and the emission peak shifts to longer wavelength continuously in the Mg2+ doping concentration range of 0.02–0.12. The emission spectra of Y2.96Ce0.04Al(4.8?y)Ga0.20MgyO12 phosphors demonstrate that the codoped Mg2+/Ga3+ ions not only induce the enhancement of Y2.96Ce0.04Al5O12 emission intensity but also lead to the red shift of Y2.96Ce0.04Al5O12 emission peak. The decay lifetimes decrease in Mg2+/Ga3+ codoped Y2.96Ce0.04Al5O12 phosphors due to defects formed by substitutions of Y3+ by Mg2+/Ga3+. 相似文献
10.
The compounds Gd14Cu48Ga3 and Tb14Cu48Ga3 have been synthesized, and their structures have been determined by powder x-ray diffraction (Gd14Ag51 type). 相似文献
11.
Weizun Zhang Xiaoyan Zhu Lijuan Wang Xin Xu Qifu Yao Weiwei Mao Xing’ao Li 《Journal of Superconductivity and Novel Magnetism》2017,30(11):3001-3005
The co-doped Bi0.95Dy0.05Fe0.95M0.05 O 3 (M = Mn, Co) samples were successfully prepared by a solid-state reaction method. At room temperature, the structural, ferromagnetic, and ferroelectric properties of the samples were measured and analyzed. An x-ray diffraction (XRD) experiment shows that co-doping leads to some structure changes. Magnetic hysteresis loops indicate that Dy-Mn and Dy-Co co-doping both can increase the ferromagnetic but the latter is superior to the former caused by the different magnetic arrangement. Furthermore, it is found that Dy-Mn co-doping is better than Dy-Co co-doping on enhancing its ferroelectricity. 相似文献
12.
A Heusler Ni50Mn29Ga16Gd5 alloy with a high transformation temperature has been obtained by substituting 5 at% Gd for Ga in a ternary Ni50Mn29Ga21 ferromagnetic shape memory alloy. The microstructure and phase transformations in the Ni50Mn29Ga16Gd5 alloy have been investigated by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and differential
scanning calorimetry. It is shown that the microstructure of the Ni50Mn29Ga16Gd5 alloy consists of matrix and hexagonal Gd (Ni,Mn)4Ga phase, which indicates a eutectic structure composed of these two phases. One-step thermoelastic martensitic transformation
occurs in this quaternary alloy. Ni50Mn29Ga16Gd5 alloy exhibits a martensite transformation start temperature up to 524 K, approximately 200 K higher than that of Ni50Mn29Ga21 alloy. At room temperature, non-modulated martensite with twin substructure is observed in Ni50Mn29Ga16Gd5 alloy. 相似文献
13.
Qinghu Guo Huajun Sun Xiaofang Liu Huiting Sui Yong Zhang Dingguo Zhou Pengdong Liu Yong Ruan 《Journal of Materials Science: Materials in Electronics》2017,28(23):17399-17404
The Bi1?+?xFe0.95Cr0.05O3 (BFCO) (x?=?0, 5, 10, 15 and 20%) thin films are fabricated on FTO/glass substrate using a chemical solution deposition method and sequential-layer annealing process. The effects of the excess Bi content on crystalline structure, morphology, and electrical performance of BFCO thin films are investigated. All the BFCO thin films are crystallized into polycrystalline perovskite structure and belonging to the space group of R3c. The BFCO thin films with 5 and 10% excess Bi contents possess no impurity phase. Especially, a dense surface morphology and columnar crystal structure can be obtained for the film with 5% excess Bi content. Especially, the one possesses superior ferroelectricity with a relative high remnant polarization (P r) of 69.8 µC/cm2 and low coercive electric field (E c) of 291 kV/cm at 1 kHz due to the relatively low leakage current density of 3.04?×?10??5 A/cm2 at 200 kV/cm. 相似文献
14.
I. V. Bodnar’ A. M. Koval’chuk V. Yu. Rud’ Yu. V. Rud’ E. I. Terukov 《Technical Physics Letters》2007,33(2):166-169
Photosensitive point structures based on CuIn2m + 1Se3m + 2 (m = 0, 1, 2) single crystals have been obtained for the first time by means of electric-discharge welding (EDW). The stationary current-voltage characteristics and the photovoltaic properties of the structures based on CuInSe2, CuIn3Se5, and CuIn5Se8 ternary semiconductors have been studied, which show evidence for the rectification effect and photoconversion. The character of interband transitions is established and the bandgap width variation in this series of compounds is traced. It is concluded that EDW can be successfully used for the fabrication of photoconverters based on multicomponent semiconductors. 相似文献
15.
In this report, an effective and simple method of selective gate sidewall recess is proposed to expose the low barrier channel at mesa sidewalls during device isolation for Al0.2Ga0.8As/ In0.15Ga0.85As PHEMTs (pseudomorphic high electron mobility transistors) by using a newly developed citric-acid-based etchant with high selectivity (> 250) for GaAs/Al0.2Ga0.8As or In0.15Ga0.85As/Al0.2G0.8 As interfaces. After sidewall recess, a revealed cavity will exist between the In0.15Ga0.85As layers and gate metals. Devices with 1 × 100μm2 exhibit a very low gate leakage current of 2.4μA/mm even at VGD = −10 V and high gate breakdown voltage over 25 V. As compared to that of no sidewall recess, nearly two orders of reduction in magnitude of gate leakage current and 100% improvement in gate breakdown voltage can be achieved. 相似文献
16.
The curves of thermally stimulated luminescence of Gd3Ga3Al2O12:Ce3+ ceramics (a nominally pure sample and samples doped with rare-earth ions) are measured in the temperature range of 80–550 K. The depth and the frequency factor of electron traps established by Eu and Yb impurities are determined. An energy-level diagram of rare-earth ions in the bandgap of Gd3Ga3Al2O12 is presented. 相似文献
17.
The magnetic, thermal, and transport properties of martensitic phase transformation in single crystal Co5Ni2Ga3 have been investigated. The single crystal Co5Ni2Ga3 shows martensitic transformation at 251 K on cooling and 254 K on warming. Large jumps in the temperature-dependent resistance
curve, temperature-dependent magnetization curve, and temperature-dependent thermal conductivity curve are observed at martensitic
transformation temperature (T
M). Negative magnetoresistance due to spin disorder scattering was observed in Co5Ni2Ga3 single crystal at all temperature range. The temperature-dependent negative magnetoresistance shows a peak at T
M, which indicates that the spin disorder increases in the process of phase transition. Co5Ni2Ga3 sample exhibits a temperature dependence of thermal conductivity κ(T) (dκ/dT > 0) due to electrons being above temperature 100 K. 相似文献
18.
A. T. M. K. Jamil H. Noguchi K. Shiratori T. Kondo H. Munekata 《Journal of Superconductivity and Novel Magnetism》2005,18(3):321-324
Ga–As–Fe composite films prepared by molecular beam epitaxy at 600°C on GaAs(100) substrates with the stacking sequence of
[100-nm GaAs/50-nm Fe3Ga2−
x
As
x
/100-nm GaAs] exhibit the distinct photo-enhanced magnetization at room temperature. Transmission electron microscopy reveals
the formation of metamagnetic Fe3Ga4 grains on the sample surface. Illumination power dependence of the enhanced magnetization has been carefully compared with
the antiferromagnetic-type magnetization–temperature (M–T) curve (Neel temperature of T
N = 340–390 K), from which we have discussed the existence of photon-mode photo-enhanced magnetization of some sort in addition
with the enhancement due to the light-induced heating. 相似文献
19.
Changhyun Jin Hyunsoo Kim Kyungjoon Baek Hyoun Woo Kim Chongmu Lee 《Journal of Materials Science: Materials in Electronics》2010,21(11):1154-1158
TiO2-sheathed Ga2O3 one-dimensional (1D) nanostructures were synthesized by thermal evaporation of GaN powders and then sputter-deposition of
TiO2. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis results indicate that the Ga2O3 cores are of a single crystal nature with a monoclinic structure while the TiO2 shells are amorphous. Photoluminescence (PL) emission is slightly decreased in intensity by TiO2 coating, but it is significantly increased by thermal annealing in an oxygen atmosphere. The emission peak is also shifted
from ~500 to ~550 nm by oxygen annealing. The increase in the green emission is due to the increase in the concentration of
the Ga vacancies in the cores by the inflow of oxygen during oxygen annealing. On the other hand, annealing in a nitrogen
atmosphere leads to a red shift of the emission to ~700 nm originating from nitrogen doping. 相似文献
20.
M. R. Mohammadi M. Ghorbani M. C. Cordero-Cabrera D. J. Fray 《Journal of Materials Science》2007,42(13):4976-4986
Nanostructured and nanoporous TiO2–Ga2O3 films and powders with various Ti:Ga atomic ratios and high specific surface area (SSA) have been prepared by a new straightforward
particulate sol–gel route. Titanium isopropoxide and gallium (III) nitrate hydrate were used as precursors and hydroxypropyl
cellulose (HPC) was used as a polymeric fugitive agent (PFA) in order to increase the SSA. X-ray diffraction (XRD) and Fourier
transform infrared spectroscopy (FTIR) revealed that powders contained both rhombohedral α-Ga2O3 and monoclinic β-Ga2O3 phases, as well as anatase and rutile. It was observed that the Ga2O3 formed from the nitrate precursor retarded anatase-to-rutile transformation. Furthermore, transmission electron microscope
(TEM) analysis also showed that Ga2O3 hindered the crystallisation and crystal growth of powders. SSA of powders, as measured by Brunauer–Emmett–Teller (BET) analysis,
was enhanced by introducing Ga2O3. Ti:Ga = 50:50 (at%/at%) binary oxide annealed at 500 °C produced the smallest crystallite size (2 nm), the smallest grain
size (18 nm), the highest SSA (327.8 m2/g) and the highest roughness. Ti:Ga = 25:75 (at%/at%) annealed at 800 °C showed the smallest crystallite size (2.4 nm) with
32 nm average grain size and 40.8 m2/g surface area. Ti:Ga = 75:25 (at%/at%) annealed at 800 °C had the highest SSA (57.4 m2/g) with 4.4 nm average crystallite size and 32 nm average grain size. One of the smallest crystallite size and one of the
highest SSA reported in the literature is obtained, and they can be used in many applications in areas from optical electronics
to gas sensors. 相似文献