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One of the key challenges for future electronic memory and logic devices is finding viable ways of moving from today's two-dimensional structures, which hold data in an x-y mesh of [...]

The effects of the molecular organization of cholesterol-superlattice versus random-on the structure of and interactions between lipids and water in lipid bilayers of cholesterol and 1-palmitoyl-2-oleoylphosphatidylcholine (cholesterol/POPC) at a fixed cholesterol mole fraction of 0.40 are studied. Results reveal that the lateral distribution of cholestrol in the superlattice bilayer is more stable than in the random bilayer.

A set of symmetric and asymmetric superlattices with ferromagnetic [La.sub.0.6][Sr.sub.0.4]Mn[O.sub.3] (LSMO) and ferroelectric 0.7Pb([Mg.sub.1/3][Nb.sub.2/3][O.sub.3]-0.3(PbTi[O.sub.3]) as the constituting layers is fabricated on LaNi[O.sub.3] coated (100) oriented LaAl[O.sub.3]. The results conclude that the conducting LSMO layer is responsible for the leaky nature of the symmetric set of superlattices.

The band structure and light emission spectra from p-doped quaternary ([Al.sub.x][In.sub.1-x-y][Ga.sub.Y])N/([Al.sub.x][In.sub.1-x-y][Ga.sub.y)]N superlattices (SLs) in zinc blend structure are examined using effective mass theory. The results provide guidelines for the interpretation of group-III nitride based alloy systems.

Fractal superlattices consist of a series of thin layers of two semiconductor materials alternately deposited on each other with widths corresponding to the rules of construction of a fractal set. The scattering of electrons in superlattices is obtained using the transfer matrix method for generalized Cantor fractal potentials that are characterized by a lacunarity parameter. The numerical results show the self-similarity of the reflection coefficient and the appearance of lacunarity-independent energies with perfectly transparent tunneling due to the bound states of the particle in each of the individual potential wells. [DOI: 10.1119/1.2209242]

The systematic assembly of nanoscale constituents into highly ordered superlattices is of significant interest because of the potential of their multifunctionalities and the discovery of new collective properties. However, successful observations of such superlattice-associated nanoscale phenomena are still elusive. Here, we present magnetic superlattices of Co and [Fe.sub.3][O.sub.4] nanoparticles with multidimensional symmetry of either AB (NaCl) or A[B.sub.2] (Al[B.sub.2]). The discovery of significant enhancement ([approximately equal to] 25 times) of ferrimagnetism is further revealed by forming previously undescribed superlattices of magnetically soft-hard [Fe.sub.3][O.sub.4]@Co[Fe.sub.2][O.sub.4] through the confined geometrical effect of thermally driven intrasuperlattice phase transition between the nanoparticulate components. binary superlattices | magnetic nanoparticle

The electronic properties of (ZnSe)(sub n)/(Si(sub 2))(sub m) (111) superlattices (SLs) were investigated theoretically in order to understand the general features of the zone-folding and the band-mixing effects in SLs composed of an indirect-band-gap semiconductor (Si). It was found that the heterointerface bond relaxation strongly affects the interface-band formation and the features of the interface bands depend on the ZnSe/Si semicondcutors species and also on interface orientations.

The emission behavior of binary-binary type-II InAs/GaSb superlattice photodiodes was studied in the spectral range between 8 to 13 mum. By evaluating the temperature dependence of the internal quantum efficiency of the radiative process, the Auger coefficient for n-type superlattice materials could be determined where the signature of an Auger-limited low-gap diode was seen as strong decrees of the internal quantum efficiency with increasing injection current.

Novel magnetic materials with ultra-high magnetic moment are presented. The [Fe.sub.70] [Co.sub.30] alloy is known to have the highest saturation magnetization of 2.45 T in nature. On the other hand, sputtered [Fe.sub.70] [Co.sub.30] :Pd and [[Fe.sub.70] [Co.sub.30]/Pd].sub.n] super-lattice films revealed higher saturation magnetization of 2.49 and 2.57 T at room temperature, respectively, while that of a [Fe.sub.70] [Co.sub.30] single-layered film was 2.38 T. These values seemed to be acceptable of a main pole material of the write head in the hard-disk drive with an areal recording density above 160 Gbits/[in.sup.2]. In addition, these films can be synthesized using a conventional sputtering apparatus as same as a [Fe.sub.70] [Co.sub.30] films. Therefore, these films will promise a feasible way for the increase of an areal recording density without any additional technologies, such as a heat assisted recording, contact recording, or further development of the media. Index Terms--[Fe.sub.70] [Co.sub.30], magnetic moment, Pd, saturation magnetization, sputtered film, super-lattice.

The electroluminescence of a Type II InAs-GaSb superlattice heterodiode is studied as a function of injection current and temperature in the spectral range. At high injection currents and elevated temperatures the band to band transitions of both superlattices can be observed.

Analyses made by optical, fluorescence and transmission electron microscopy showed that individual faceted superlattices are composed of nearly single-size nanocrystals assembled into fcc lattices. Photoluminescence is measured in individual superlattices and the results are compared to the same measurements made in amorphous solid layers and solutions of nanocrystals.

A study investigates the influence of operation voltages and doping densities on superlattice infrared photodetectors (SLIPs) with a single current blocking layer. The results show that the measurement data and the simulation results are identical for devices applied under different voltages and with different quantum-well doping densities.

Polycrystalline samples of beta-KxBa(1-x)Cu2S2 with a natural superlattice structure were prepared and the thermoelectric properties from room temperature to about 850 K were measured. The thermal conductivities of potassium-doped samples are slightly higher than those of undoped samples as a result of electronic contributions.

A study demonstrates the resonant-ultrasound spectroscopy and laser-Doppler interferometry can determine anisotropic elastic constants of superlattice thin films. The results show that the mechanical resonance frequencies of a layered specimen composed of a substrate and deposited thin film depend on the elastic constants, mass densities, and dimensions of the substrate and thin film.

ZnO:In nanowires with superlattice structure have been synthesized by evaporating ZnO, In2O3, and Co2O3 mixed powders. A growth model based on the vapor-liquid-solid mechanism has been proposed for interpreting the growth of nanowires.

Photoelectron relaxation in the second miniband of a superlattice is investigated with a high-pass energy filter at one end of the supperlattice.

The field-induced carrier redistribution is examined for superlattices (SL) with four wells in each unit well.

The photoluminescence properties of InAs/GaAs self-assembled quantum dots are investigated.

Research into the characteristics of the in-plane optical anisotropy in the symmetric and the asymmetric (001) GaAs/Al(Ga)As superlattices is presented. The observed anisotropy was found to be not only determined by the heavy-hole-light-hole mixing at the zone centre. It is still possible to use the band-to-band transitions to interpret the main features.

Bi2Te3/Sb2Te3 superlattices were deposited on GaAs using noncontact pulsed laser heating and thermoreflectance thermometry, and thermally characterized.

Step-grade short period (Sim/Gen)n superlattices were used in the growth of Si0.75Ge0.25 alloy layers on Si(001) substrates.

La0.7Ca0.3Mn0/Yba2Cu307 superlattices were studied to determine their magnetic and superconducting properties.

Si/SiO2 superlattices were studied using Raman scattering and photoluminescence.

The use of graded superlattice active regions in high duty cycle operation of quantum cascade superlattice lasers is discussed.

Research describing the phase transition behavior of zirconium titanate is presented. In particular the process of cation ordering and its relation to lattice contraction are investigated by Raman scattering and x-ray diffraction methods.

Research describing photoluminescence excitation measurements of quantum dot superlattice materials is presented. In particular the effects of excitation densities on the spectral shape are investigated.

The fabrication of two InGaP/GaAs resonant tunneling bipolar transistors with different superlattice structures in the emitters is described.

Research into superlattice avalanche photodiodes is presented. Results and discussions are included.

Research describing light emission from silicon based nanostructures is presented. In particular the electroluminescence of amorphous Si/SiO2 superlattices is investigated.

Research describing interband transitions in Bragg confining structures is presented. In particular the effect of distributed Bragg reflectors on above-barrier electron states is investigated.

A demonstration that highly ordered nanocrystals superlattices can be achieved if stable wetting layer of solvent is maintained on the substrate is presented. It is found that the superlattice structures are robust and the final dewetting of the solvent does not perturb them.

Semiconductor superlattices were studied to determine nonlinear terahertz oscillations.

A numerical solution to the wave equation was used to study the long-wavelength sound velocities for a model of two component elastic superlattices composites.

Magnetron sputtering was used to grow strained layer superlattices of GaAs/Ge/GaAs and Ge/GaAs/Ge.

The atomic order of B site ions were adjusted to artificially control the magnetic properties of LaFeO3-LaCrO3 superlattices.

The first report of minority electron transport anisotropy in AlxGa1-xN/GaN superlattices.

Research describing the photoluminescent properties of strained layer superlattice samples is presented. Fourier transform infrared absorbance spectroscopy is studied for various thicknesses of GaSb layers.

Research describing strain relaxation in semiconductor alloys is presented. In particular the characteristics of superlattices grown on thick GaN buffer layers are investigated .

Research describing elctroluminescence spectra studies of silicon based superlattice structures is presented. In particular the location and conditions necessary for originating electroluminescence are investigated.

Four interface modes were seen in both (XX) and (XY) geometries in the resonant Raman spectra of ultrathin GaAs/A1As superlattices.

Raman scattering measurements were used to characterize InP/InGaAs superlattices.

Research describing the growth of natural strained layer superlattice structures is presented. In particular the relationship between temperature and the size and thickness of the platelets is investigated.

A new study uses electron microscopy and spectroscopy techniques to investigate the chemical and structural characteristics of FexMn1-x alloys in FexMn1-x/Ir superlattices.

A description of laser-induced transient enhanced diffusion in laser-annealed nonstoichiometric AlAs/GaAs heterostructures is presented.

The dynamic properties of weakly coupled superlattices were studied.

Thin films of Fe and Cr intercalated superlattices were synthesized.

Phase-coherent electron transport is studied through potential barriers in a quantum-dot superlattice.