Superlattices and Microstructures (Superlattice Microst )

Journal description

An Interdisciplinary Journal on the Science and Technology of Nanostructures. Superlattices and Microstructures is a journal devoted to the science and technology of synthetic microstructures, microdevices, surfaces and interfaces. The last decade has seen rapid developments in the fabrication, characterization and conceptual understanding of synthetic microstructures in many different material systems including silicon, III-V and II-VI semiconductors, metals, ceramics and organics. The objective of this journal is to provide a common interdisciplinary platform for the publication of the latest research results on all such"nanostructures" with dimensions in the range of 1 - 100 nm; the unifying theme here being the dimensions of these artificial structures rather than the material system in which they are fabricated.

Current impact factor: 1.98

Impact Factor Rankings

2015 Impact Factor Available summer 2015
2013/2014 Impact Factor 1.979
2012 Impact Factor 1.564
2011 Impact Factor 1.487
2010 Impact Factor 1.091
2009 Impact Factor 0.91
2008 Impact Factor 1.211

Impact factor over time

Impact factor
Year

Additional details

5-year impact 1.30
Cited half-life 5.40
Immediacy index 0.28
Eigenfactor 0.01
Article influence 0.34
Website Superlattices and Microstructures website
Other titles Superlattices and microstructures (Online), Superlattices and microstructures
ISSN 1096-3677
OCLC 36952870
Material type Document, Periodical, Internet resource
Document type Internet Resource, Computer File, Journal / Magazine / Newspaper

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: We have studied a temporal and spectral behavior of the photoluminescence of the colloidal PbS quantum dots (QDs) with a controlled spacing between QDs. The high-speed streak camera system combined with a monochromator was used to obtain the time evolution of the luminescence spectrum itself.
    Superlattices and Microstructures 03/2015; 79.
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    ABSTRACT: Epitaxial trilayers consisting of ferromagnetic (FM) metallic Pr0.7Sr0.3MnO3 (PSMO) and antiferromagnetic (AFM) insulators La0.5Ca0.5MnO3 (LCMO) were fabricated on (0 0 1)-oriented single crystal MgO substrates using pulsed laser deposition technique. High resolution X-ray diffraction (HRXRD), grazing incidence X-ray reflectivity (GIXRR) and atomic force microscope were applied to characterize the surface and interface structure of PSMO/LCMO/PSMO trilayers. The HRXRD patterns of all trilayers implied high quality of epitaxial layer. A structural model including seven layers was presented to theoretically simulate GIXRR data. The perfect GIXRR data fitting of the trilayers indicated that the thickness of the top sublayer at air/PSMO interface was about 2.5 nm for all the samples and the mass density of the top sublayer was about 77.66% of PSMO layer. In all trilayers, there existed two disordered layers with thickness of about 4 nm resulting from interdiffusion at the PSMO/LCMO interfaces. The root-mean-square (rms) roughness of the surface and interface in the trilayers varied with respect to the thickness of LCMO layer. The surface roughness was consistent with observation from atomic force microscopy. A further analysis indicated that the rms roughness was related to the mismatch strain relaxation in film. Moreover, studies on magnetic properties of PSMO/LCMO/PSMO trilayers show that ferromagnetic clusters at the interface, large roughness at the surface and interface and interdiffusion between PSMO and LCMO layer probably lead to the disappearance of exchange bias.
    Superlattices and Microstructures 03/2015; 79.
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    ABSTRACT: Hexagonal wurtzite ZnO nanoparticles were successfully synthesized in aqueous solutions containing zinc acetate (Zn(OAc)2) and sodium hydroxide (NaOH) by microwaving at 400, 600 and 800 W for 6 min. The as-synthesized products analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectroscopy were pure hexagonal wurtzite ZnO nanostructure with sharp and strong optical phonon Raman-active mode of E2H at 438.7 cm−1 and in the shape of nanoparticles clustered together as nanoplate–nanorod mixture with different orientations. The central photoluminescence (PL) emission was detected at 378.9–382.4 nm of UV region, due to the recombination of excitons. The energy band gap of the as-synthesized products characterized by UV–visible absorption spectroscopy was decreased form 3.20 eV to 3.01 eV by increasing in the microwaving power from 400 W to 800 W, due to the decreasing in the full width at half maximum (FWHM) of the XRD main peaks and the improvement of crystalline degree of the products.
    Superlattices and Microstructures 02/2015; 78.
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    ABSTRACT: In this work, the optical rectification and the second harmonic generation coefficients in a strained InGaN/AlGaN quantum well are studied. Impacts of the spontaneous and piezoelectric polarization fields on the potential profile are taken into account. The energy levels and wave functions are calculated using the fourth-order Runge–Kutta method and optical properties are obtained using the compact density matrix approach. Effects of intense laser field, In composition, Al composition, the well width and barrier width on the second-order nonlinear optical properties are investigated. Results reveal that the confinement potential is considerably affected by the laser field and internal electric field. Results also indicate that the resonant peaks experience a red-shift with increasing the laser field strength and barrier width. Moreover, the resonant peaks suffer a blue-shift with the increase in In and Al compositions.
    Superlattices and Microstructures 02/2015; 78.
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    ABSTRACT: The structural stability, electronic properties and adsorption characteristics of CO on pure and Mo substituted WO3 are optimized and studied using density functional theory with B3LYP/LanL2DZ basis set. Structural stability of both hexagonal and orthorhombic phases of WO3 nanostructures is discussed with calculated energy. The electronic properties of WO3 are analyzed in terms of HOMO–LUMO gap, ionization potential and electron affinity. Dipole moment and point group of pure and Mo substituted WO3 nanostructures are also studied. The significance of the present work is to give clear insights into the adsorption characteristics of CO on orthorhombic and hexagonal WO3 nanostructures. The adsorption characteristics of CO can be enhanced with the substitution of Mo impurity in the WO3 base material. The adsorption characteristics CO on WO3 are reported in terms of adsorbed energy, average energy gap variation, Mulliken population analysis and density of states spectrum. The best adsorption sites of CO onto hexagonal and orthorhombic phases of WO3 nanostructures are identified and reported.
    Superlattices and Microstructures 02/2015; 78.
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    ABSTRACT: Electrical performance of highly scaled III-nitride Ga-face and N-face HEMTs have been investigated using a two-dimensional numerical simulator. Four HEMT structures were studied, in three of which GaN substrate were grown in Ga-polar direction and in the last structure GaN substrate was grown in N-polar direction. Simulation results indicate that N-face structure has superior performance as compared with Ga-face structures. The undesirable effects originated from a potential distribution in the channel and current injection through the buffer effectively decrease and therefore their resultant effects such as low output conductance, threshold voltage shift and soft pinch-off become much less noticeable in N-face HEMT structure as compared with Ga-face HEMTs with similar geometry. Furthermore, superior small signal, high frequency characteristics as compared to Ga-face HEMTs structures can be achieved.
    Superlattices and Microstructures 02/2015; 78.
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    ABSTRACT: Fe-doped nanocrystalline gallium nitride (GaN) photocatalysts were prepared by the reaction of Ga2O3, NH4Cl, metallic Mg powder and Fe2(SO4)3 powder in an autoclave at 650 °C. The prepared photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS) and UV–vis reflectance spectroscopy (DRS). The photocatalytic activity was evaluated by the photocatalytic degradation of Rhodamine-B (RhB) solution under ultraviolet light irradiation. The highest photocatalytic degradation activity was observed when the content of Fe dopant is 1.0 wt%, which is almost 4 times higher than that of the undoped GaN. The mechanism of enhanced photocatalytic activity was also discussed.
    Superlattices and Microstructures 02/2015; 78.
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    ABSTRACT: In this paper the exciton and electron sates in cylindrical quantum dot with Morse potential made of GaAs are studied. For the regime of strong size quantization, energy spectrum with the parabolic approximation case are compared. For strong and weak size quantization regimes analytic expressions for the particle energy spectrum, absorption coefficient and dependencies of effective threshold frequencies of absorption on the geometrical parameters quantum dot are obtained. For the intermediate size quantization regime the problem solved in the framework of variation method. The selection rules corresponding to different transitions between quantum levels are found. The size dispersion distribution of growing quantum dots by the radius and height by two experimentally realizing distribution functions have been taken into account. Distribution functions of Gauss, Lifshits-Slezov have been considered.
    Superlattices and Microstructures 02/2015; 78.
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    ABSTRACT: A novel simulation approach for the breakdown characteristics of SOI high-voltage (HV) PMOS in a fixed power supply application is proposed. The different optimized parameters for the SOI HV PMOS can be achieved by the conventional and proposed simulation approaches. A SOI variation of lateral doping (VLD) field PMOS, which is widely used in the level-shift circuit is investigated by the conventional and novel simulation approaches. For the level-shift circuit with power supply of 400 V, the breakdown voltage (BV) of the optimized SOI VLD field PMOS increases from 520 V with the conventional simulation approach to 646 V with the proposed simulation approach. Moreover, the corresponding optimized doping concentration of p-drift region with the proposed approach is higher than that with the conventional approach, thus greatly reducing the specific on-resistance (Ron,sp). The SOI VLD field PMOS actually has a more robust breakdown voltage and lower Ron,sp in the fixed power supply. The BV and Ron,sp of SOI HV PMOS can be truly reflected and the effect of reduced bulk field (REBULF) is revealed in the fixed HV power supply by employing the novel simulation approach.
    Superlattices and Microstructures 02/2015; 78.
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    ABSTRACT: Cobalt substituted manganese nanocrystalline spinel ferrites having general formula CoxMn1-xFe2O4 was successfully synthesized using hydrothermal method. The structure, magnetic and dielectric properties of as-synthesized samples was characterized through different techniques such as XRD, FESEM, EDX, FTIR, PPMS and Dielectric spectroscopy. X-ray diffraction (XRD) studies showed that the samples have pure cubic spinel phase. The lattice parameter enhances with Co substitution. The SEM images of CoxMn1-xFe2O4 ferrite show that the grain size decreases with an increase in the Co content and the average nanocrystalline sizes were found to be less than 100 nm. Compositional stoichiometry was confirmed by energy dispersive analysis of the X-ray (EDAX) technique. The FTIR spectra reveled two prominent frequency bands in the wave number range 400–600 cm–1 which confirm the cubic spinel structure and completion of chemical reaction. As the cobalt concentration increases, the magnetization of the octahedral sites and hence the net magnetization decreases. It is also observed that the saturation magnetization (Ms), decrease while coercivity (Hc) increase with increase in cobalt substitution. Frequency dependence of dielectric constant shows dielectric dispersion due to the Maxwell–Wagner type of interfacial polarization. AC conductivity measurements suggest that the conduction is due to small polaron hopping.
    Superlattices and Microstructures 02/2015; 80.
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    ABSTRACT: Iron doped indium oxide thin films were grown by chemical spray pyrolysis technique at different concentrations y = [Fe2+]/[In3+] (y= 0, 2, 4 and 6 at.%). Structural, morphological, optical and electrical properties were studied by X-ray diffraction, Raman spectroscopy, atomic force microscopy, spectrophotometer, fluorescence spectrometer and Hall Effect. The XRD analyses show that indium oxide crystallizes into cubic structure with (222) as a preferred orientation. An enhancement of the crystallinity followed by a change in plan orientation from (222) to (400) was observed when iron doping concentrations is increasing. The optimum of In2O3 crystal structure is obtained for iron concentration equals to 6at.%. Transmission and reflection spectra reveal the presence of interference fringes with oscillatory character indicating the good uniformity and optical homogeneity of deposited films. The obtained band gap energy Eg is in the range of [3.29–3.45] eV. The single oscillator energy E0 and dispersion energy Ed were determined by Wemple model using the envelope method applied for all obtained XRD spectra. We found that E0=2 x Eg for iron doped films and E0=1.5 x Eg for undoped ones. Measured electrical resistivity decreases from ρ= 6502 x 10-4 to 197.9 x 10-4 Ω.cm for respectively undoped and In2O3:Fe(6at.%) thin films. A heat treatment was carried out at different temperatures (200°C, 300°C and 400°C) under nitrogen atmosphere to try to reduce more electrical resistivity. We found that it decreases to about 26.94 x 10-4 Ω.cm for 300°C annealing temperature.
    Superlattices and Microstructures 02/2015;
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    ABSTRACT: The effect of the external electric field on the basic parameters of interface polarons in wurtzite nitride cylindrical nanowire (NW) is studied theoretically by means of Lee–Low–Pines variational approach. The analytical expressions for the quasi-one-dimensional Fröhlich polaron self-energy and effective mass are obtained as functions of the wire radius and the strength of the electric field applied perpendicular to the wire axis. It is found that the main contribution to the polaron basic parameters is from zero-order IO phonon mode. The numerical results on the GaN material show that the polaron self-energy (effective mass) increases with the increase of the electric field and is more sensitive to the field when the wire radius is larger. It is also found that the polaron self-energy in GaN NWs is bigger than that in zinc bland GaAs-based cylindrical NWs. The obtained results will be very useful for further investigation of the optical and transport phenomena related to polaron motion in wurtzite nitride cylindrical NWs, when the Stark effect competes with the spatial quantum confinement and will have significant practical meanings for optoelectronic devices, such as light-emitting and laser diodes, ultraviolet photodetector designs and applications.
    Superlattices and Microstructures 01/2015; 77.