Search

We report an experimental study of proximity effect-induced superconductivity in crystalline Cu and Co nanowires and a nanogranular Co nanowire structure in contact with a superconducting W-based floating electrode (inducer). For electrical resistance measurements up to three pairs of Pt-based voltage leads were attached at different distances beside the inner inducer electrode, thus allowing us to probe the proximity effect over a length of 2-12 lm. Up to 30% resistance drops with respect to the normal-state value have been observed for the crystalline Co and Cu nanowires when sweeping the temperature below Tc of the inducer (5.2 K). By contrast, relative R(T) drops were found to be an order of magnitude smaller for the nanogranular Co nanowire structure. Our analysis of the resistance data shows that the superconducting proximity length in crystalline Cu and Co is about 1 μm at 2.4 K, attesting to a long-range proximity effect in the Co nanowire. Moreover, this long-range proximity effect is insusceptible to magnetic fields up to 11 T, which is indicative of spin-triplet pairing. At the same time, proximity-induced superconductivity in the nanogranular Co nanowire is strongly suppressed due to the dominating Cooper pair scattering caused by its intrinsic microstructure. [ABSTRACT FROM AUTHOR]

The processes of charge accumulation in the MOS structures with SiO2 films containing Si nanocrystals are investigated, depending on the conditions of their formation by pulsed laser deposition. High-frequency capacity-voltage characteristics of structures with the different thicknesses of films, sizes of Si nanocrystals, and their densities in the case of doping the films with gold and without it are measured. It is shown that the positive and negative charges are built-in, respectively, in the undoped films and those doped with gold. At the record of C-V curves, the accumulation of a positive charge is observed. The value of accumulated charge is higher in thin films and in the films doped with gold. The obtained results testify the possibility of the use of pulsed laser deposition for creation of memory structures based on the charge capture by Si nanocrystals. [ABSTRACT FROM AUTHOR]

CoPt–C binary alloys have been fabricated by focused-electron-beam-induced deposition by the simultaneous use of Co2(CO)8 and (CH3)3CH3C5H4Pt as precursor gases. The alloys are made of CoPt nanoparticles embedded in a carbonaceous matrix. TEM investigations show that as-grown samples are in an amorphous phase. By means of a room temperature low-energy electron irradiation treatment the CoPt nanoparticles transform into face-centered tetragonal L10 nanocrystallites. In parallel, the system undergoes a transition from a superparamagnetic to a ferromagnetic state at room temperature. By variation of the post-growth irradiation dose the electrical and magneto-transport properties of the alloy can be continuously tuned. [ABSTRACT FROM AUTHOR]

Objective: To establish predictive factors of patients who failed intra-cavernosal injection therapy and ultimately required corporoglandular shunting during first-time ischemic priapism episodes., Methods: A retrospective review was performed of all patients over the age of 18 who presented to our institution with first-time episode of ischemic priapism from 2009 to 2019. Variables assessed included: body mass index, diabetes, hypertension, race, insurance-type, hypertension, etiology, age, duration of erection prior to evaluation, total amount of phenylephrine injected, and use of corporal irrigation. A receiver operating characteristic (ROC) curve was performed utilizing duration of erection and amount of phenylephrine., Results: One-hundred and forty-seven patients met inclusion criteria of which 24 patients required surgical intervention. There were differences associated with mean total phenylephrine used, duration of erection between shunted patients and non-shunted patients with regards to age (P = .38) or etiology (P = .81). Multivariable analysis revealed differences between duration of erection and BMI greater than 25 kg/m 2 . ROC curve analyses revealed total amount of phenylephrine injected and duration of erection were acceptable and excellent predictors of need for shunt procedures with area under the curves of 0.72 and 0.90, respectively. Optimal cut-off values for each were found to be 950 mcg and 15.5 hours., Conclusion: Our study suggests that patients who require greater than 950 mcg of total phenylephrine or present with erections lasting greater than 15.5 hours are significantly more likely to require corporoglandular shunting and should be counseled appropriately as such., (Copyright © 2021 Elsevier Inc. All rights reserved.)

We present experimental results and theoretical simulations of the adsorption behavior of the metal-organic precursor Co(2)(CO)(8) on SiO(2) surfaces after application of two different pretreatment steps, namely by air plasma cleaning or a focused electron beam pre-irradiation. We observe a spontaneous dissociation of the precursor molecules as well as autodeposition of cobalt on the pretreated SiO(2) surfaces. We also find that the differences in metal content and relative stability of these deposits depend on the pretreatment conditions of the substrate. Transport measurements of these deposits are also presented. We are led to assume that the degree of passivation of the SiO(2) surface by hydroxyl groups is an important controlling factor in the dissociation process. Our calculations of various slab settings, using dispersion-corrected density functional theory, support this assumption. We observe physisorption of the precursor molecule on a fully hydroxylated SiO(2) surface (untreated surface) and chemisorption on a partially hydroxylated SiO(2) surface (pretreated surface) with a spontaneous dissociation of the precursor molecule. In view of these calculations, we discuss the origin of this dissociation and the subsequent autocatalysis.