We develop a theory for laser-induced periodic surface structure by associating each Fourier component of induced with the corresponding inhomogeneous energy deposition just beneath surface. assume that roughness, confined to region height much less than wavelength light, is responsible symmetry breaking leading this deposition; we find strong peaks in space, which leads predictions fringe patterns spacing and orientation dependent on angle incidence polarization damaging beam. The nature...

We report the results of a detailed investigation into properties periodic damage structure that can be produced on nominally smooth surfaces solids when they are irradiated with single beam intense laser radiation. The study is primarily concerned extracting information from Fourier transform as observed via Fraunhofer diffraction pattern by reflecting cw surface. In particular, patterns in Ge, Si, Al, and brass pulsed 1.06- 0.53-\ensuremath{\mu}m radiation compared function angle incidence...

We present here the microwave surface impedance of a high-purity crystal ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{6.99}$ measured at five frequencies between 1 and 75 GHz. This data set reveals main features conductivity spectrum thermally excited quasiparticles in superconducting state. Below 20 K there is regime extremely long quasiparticle scattering times, due to both collapse inelastic below ${T}_{c}$ very weak impurity ${\mathrm{BaZrO}}_{3}$-grown used this study. Above K,...

This paper describes the design and use of a small integrating reflectometer for determining total reflection factor smoked magnesium oxide surface under diffuse illumination. It also shows how may be used absolute determination apparent factors (reflectances) parallel

The ab-plane optical conductivity of ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{6.95}$ has been studied by infrared reflectance spectroscopy in the presence disorder introduced ion irradiation. frequency dependence superconducting state suggests that irradiation caused carrier localization. Localization explains both suppression ${\mathit{T}}_{\mathit{c}}$ and reduction superfluid fraction. temperature penetration depth pure disordered supports hypothesis non-s-wave superconductivity.

Abstract Thin gold films deposited on a substrate of bismuth oxide or, better, between two oxide, are found to have exceptionally high electrical conductivity and optical transmission. Heating several hundred degrees centigrade further enhances these properties, irreversibly. Typical results, for thickness 100 å heat-treatment at 450°c, film-resistance 3 1/2 ohms ‘ per square ’ white-light transmission 75% (or 82% using controlled interference effects). The measured constants remarkably...

This paper describes experiments to elucidate the exact physical and chemical structure of selenium rectifier photocell, especially that thin surface film. A technique is described for sputtering films cadmium oxide which, though transparent in thickness required a cell, have an electrical conductivity exceeding graphite. The can be closely controlled. With such films, on pure crystalline selenium, cells were produced with white-light sensitivities over 700 µA per lumen, open-circuit...

We report our femtosecond time-resolved measurements on the photoresponse of an epitaxial YBa2Cu3O7−x (YBCO) thin-film photodetector, patterned into a microbridge geometry. By varying current–voltage biasing conditions between superconducting and resistive (hot spot) states, we observed transients that correspond to nonequilibrium kinetic-inductance electron-heating response mechanisms, respectively. The two-temperature model Rothwarf–Taylor theory have been used simulate measured wave forms...

A study is reported of the in situ growth three distinct phases LiCoO2 by laser ablation deposition on heated substrates an oxygen background. Films were characterized x-ray diffraction from which crystal structure, orientation, lattice constants, and phase information obtained. Electron microscopy was used to investigate grain size overall film morphology. For under 2000 mTorr O2, substrate temperatures 22–250 °C resulted a rock-salt 300–450 produced modified spinel structure...

Thin films of are obtained by Laser ablation from sintered targets. The were deposited on stainless steel or tantalum foil substrates so they could be used as cathodes in rechargeable thin‐film lithium batteries. amorphous when unheated substrates, but crystallize readily heated air above 500°C. Using x‐ray diffraction, we show that the basically stoichiometric and have no impurity phases present. They consist partly normal bulk phase which can prepared reacting at 850°C. However, also...

We report a detailed experimental study of the periodic surface damage induced by laser irradiation at 1.06 μm on nominally smooth Ge samples; we include novel observations obtained studying its optical diffraction pattern, which reveals previously unappreciated richness in structure. The usual ’’surface scattered wave’’ explanation is criticized; argue that results from electromagnetic fields generated inhomogeneities but that, due to presence interface between vacuum and bulk Ge, these are...

The galvanometer amplifier described in this paper follows standard practice that the beam of light reflected from mirror primary falls upon a pair selenium rectifier photocells connected series-opposition. net current cells is indicated by secondary galvanometer. Much improved stability and linearity are, however, secured use red-absorbing filter to eliminate photocell fatigue, negative feedback circuit circuit. Sufficient gain provide for secured, without valve amplification, using...

ABSTRACT The solvent extraction of palladium(II), platinum(II), platinum (IV), rhodium(III), iridium(III) and iridium(IV) from hydrochloric acid solutions by some dialkyl sulphoxides the types R2SO, RR′SO R2′SO, where R=alkyl R′=cycloalkyl, was investigated. order these metals 0.50 M di-n-hexyl sulphoxide in xylene containing 1 to 6 found be Pd(II)> Pt(II)> Ir(IV)>Pt(IV)>Rh(III)>Ir(III). Metal-distribution studies suggest that platinum(IV) are extracted form ion-pairs such as (L3ċH3O+)2IrCl6...

ABSTRACT The solvent extraction of the trivalent lanthanides and yttrium from nitrate media by solutions carboxylic acids in xylene has been studied. Commercially available such as Versatic 10 naphthenic were used, well model compounds known structure, 2-ethylhexanoic 3-cyclohexylpropanoic acids. In a few cases, metals sulphate chloride was also investigated. dependence properties on atomic number lanthanide shows definite relationship to steric bulk acid molecule quantified means parameter,...

Substrate-based catalytic growth modes have been widely used to fabricate vertically aligned nanowires for most technologically relevant semiconducting systems, with CdTe being a notable exception. The catalysts that promote one-dimensional nanoscale mode in other systems seem fail, creating the need an alternative approach. Here, we demonstrate how nanowire structures can be derived from newly developed catalytically driven process. produced are highly faceted and share epitaxial...

The interfacial misfit (IMF) dislocation array of an epitaxial GaSb film on a Si substrate has been imaged with high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). mismatch strain accommodation through formation investigated using geometric phase analysis (GPA) HAADF-STEM images atomic resolution to probe the defects’ local distribution. These measurements indicate that lattice parameter recovers its bulk value within three unit cells from interface due...

The authors deal with the present status of vacuum photocell as regards proportionality photoelectric current to incident illumination, and give a series observations which show that, while excellent cells are obtainable, their employment for precise work without previous test is unsafe. A theory developed accounts observed results gives over limited range an equation form S = K1 + K2/radicalE, where cell-sensitivity E Attention called dependence illumination characteristic upon colour light...

We have measured the photoresponse of current-biased bridge structures epitaxial ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}$ thin films on ${\mathrm{LaAlO}}_{3}$ using 100 ps, 532 nm laser pulses. Voltage transients with fast and slow components were observed below ${\mathit{T}}_{\mathit{c}}$. The amplitude component agrees a resistive bolometric response where pulse heats into transition region. decay time is consistent...

There has long been a discrepancy between microwave conductivity measurements in high temperature superconductors and the spectrum expected simplest models for impurity scattering d-wave superconductor. Here we present new type of broadband measurement surface resistance that finally shows some spectral features d(x2-y2) pairing state. Cusp-shaped spectra, consistent with weak nodal quasiparticles, were obtained 0.6-21 GHz frequency range highly ordered crystals YBa2Cu3O6.50 YBa2Cu3O6.99.