Composition spread metal thin film fabrication technique based on ion beam sputter deposition

A composition spread metal thin film fabrication technique based on ion beam sputter deposition method was developed. The technique enables us to fabricate any desired part or a complete binary/ternary composition spread metal thin films onto a single substrate by sequentially sputtering different target materials. Composition spread metal thin films can be deposited directly on a dielectric film in patterned electrode shape for C-V and I-V measurements. The system could be especially useful in the search for new multi-component metal gate materials.     

Schottky metal library for ZNO-based UV photodiode fabricated by the combinatorial ion beam-assisted deposition

A binary alloy Schottky barrier diode on zinc oxide (ZnO) was developed using the combinatorial ion beam-assisted deposition system. The compositional fraction of the binary alloy was continuously varied using the composition-spread technique, to control the Schottky barrier height. After metal deposition, patterned Schottky diodes were fabricated on a ZnO single-crystal substrate. Pt-Ru alloy was selected from the work function viewpoint. Our experiments showed that the compositional fraction of the Schottky binary alloys changed continuously as designed and the Schottky barrier heights measured by current-voltage (I-V) measurements increased with increasing Pt content. Maximum barrier height difference for ZnO was 137 meV. Using ion beam deposition in parallel with the combinatorial system showed that the Schottky barrier heights for ZnO can be controlled by binary metal alloying.     

On the S-procedure and Some Variants

We give a concise review and extension of S-procedure that is an instrumental tool in control theory and robust optimization analysis. We also discuss the approximate S-Lemma as well as its applications in robust optimization.The many suggestions and detailed corrections of an anonymous referee are gratefully acknowledged.     

Evaluation of fluid-filled fractures during acoustic measurements on tube waves

The problem of reflection, transmission, and conversion of the tube wave on a fracture intersecting a borehole is investigated. We consider the case where an acoustic sonde is placed inside a borehole and the fracture separates two different elastic half-spaces and is filled with a porous material. Bibliography: 5 titles. __________ Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 324, 2005, pp. 121–128.     

Controlled structure and density of “living” polystyrene brushes on flat silica surfaces

Thin layers of polystyrene were grown from surface-grafted nitroxide initiators via controlled “living” free radical polymerization. The “reactive” Langmuir-Blodgett deposition method allowed an effective control of the initiator layer density leading to PS brushes with different and high grafting density and stretching. The influence of the grafting density on the layer structure was studied. Comparison with theoretical predictions for monodispersed brushes in bad solvent was discussed. The thickness was found to vary linearly with molecular weight and the density dependence was shown using wetting measurements. Special features of controlled radical nitroxide polymerization from a surface were discussed. A direct comparison of the molecular weight and polydispersity between surface and bulk polymers was made by de-grafting the brushes into a toluene/HF solution. Finally, some evidence of a “surface Fischer” effect was shown from re-initiated layers. Received 20 December 2001     

Symmetry character of collective states in 104Pd populated in the EC-β+ decay of 104Ag

The states of ¹⁰⁴Pd, populated in the EC-β⁺ decay of the ground ( J ^π = 5⁺) and metastable ( J ^π = 2⁺) states of ¹⁰⁴Ag, have been investigated in the framework of the proton-neutron interacting boson model, extending a previous analysis to take into account the newly appeared experimental data. All positive-parity states up to an excitation energy of 3 MeV and spin in the range J = 1-6, fed by more than 0.3% in the decay of the parent nucleus, have been considered. As a result, strong evidence has been found for interpreting most of these states as states of collective nature having a quite pure full- or mixed-symmetry character and, in particular, for identifying the 1⁺ level at 2276 keV as the lowest 1⁺ mixed-symmetry state.     

Illusions of vision: Interpretation within the framework of a holographic model

Several illusions of vision are considered on the basis of a neurophysiological holographic model of visual perception at the level of the eye’s and the retina. It is suggested that the eye’s optical system forms a spatial spectrum of the observed object rather than its image on the retina. The spectrum is encoded by active anisotropic quasi-crystalline structures of rod rhodopsins and cone iodopsins, and a complex Fourier hologram of the observed object consisting of two quadrature components is recorded. The holographic hypothesis is confirmed by the results obtained by digital simulation.     

A historical note on the entropy principle of Müller and Liu

Received July 12, 2001 / Published online February 28, 2002     

Combined confocal and magnetic resonance microscopy

Confocal fluorescence optical microscopy and magnetic resonance microscopy are each used to study live cells in a minimally invasive way. Both techniques provide complementary information. Therefore, by examining cells simultaneously with both methodologies, more detailed information is obtained than is possible with each microscope individually. In this paper two configurations of a combined confocal and magnetic resonance microscope are described. The first configuration is capable of studying large single cells or three-dimensional cell agglomerates, whereas the second configuration is designed for the investigation of monolayers of mammalian cells. In both cases the sample compartment is part of a temperature regulated perfusion system. Images obtained with the combined system are shown forXenopus laevis oocytes, model JB6 tumor spheroids, and a single layer of Chinese hamster ovary cells. Finally, potential applications of the combined microscope are discussed.