Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
In this article we investigate the surface spin polarization in a 100 nm Co2Cr0.6Fe0.4Al (CCFA) film grown ex situ epitaxially on MgO(100) with a 10 nm Fe buffer layer by means of spin resolved photoemission. We show that a careful in situ preparation of the sample surface leads to values for the room temperature spin…
A novel mechanistic approach is proposed for the prediction of the life of thermal barrier coating (TBC) systems. The life prediction methodology is based on a criterion linked directly to the dominant failure mechanism. It relies on a statistical treatment of the TBC's morphological characteristics, non-destructive s…
Thin films of strongly-correlated electron materials (SCEM) are often grown epitaxially on planar substrates and typically have anisotropic properties that are usually not captured by edge-mounted four-terminal electrical measurements, which are primarily sensitive to in-plane conduction paths. Accordingly, the correl…
We studied the optical absorption induced by 4.7eV pulsed laser radiation on Ge-doped a-SiO2 synthesized by a sol-gel technique. The absorption spectra in the ultraviolet spectral range were measured during and after the end of irradiation with an in situ technique, evidencing the growth of an absorption signal whose…
Epitaxial thin films of the theoretically predicted half metal Co 2 Cr 0.6 Fe 0.4 Al were deposited by dc magnetron sputtering on different substrates and buffer layers. The samples were characterized by x-ray and electron beam diffraction (RHEED) demonstrating the B2 order of the Heusler compound with only a small fr…
Co$_2$FeSi(100) films with L2$_1$ structure deposited onto MgO(100) were studied exploiting both longitudinal (LMOKE) and quadratic (QMOKE) magneto-optical Kerr effect. The films exhibit a huge QMOKE signal with a maximum contribution of up to 30 mdeg, which is the largest QMOKE signal in reflection that has been meas…
A Co$_2$FeSi (CFS) film with L2$_1$ structure was irradiated with different fluences of 30 keV Ga$^+$ ions. Structural modifications were subsequently studied using the longitudinal (LMOKE) and quadratic (QMOKE) magneto-optical Kerr effect. Both the coercivity and the LMOKE amplitude were found to show a similar behav…
The photoluminescence properties of a silicate glass coactivated with silver and erbium ions were studied. Absorption and photoluminescence spectra allowed to distinguish in the glasses several active species related to the silver, whose ratio depends on heat treatment and silver concentration. The broad emission of s…
Theoretical calculations of the elastic response of carbon composites and amorphous carbon are reported. The studied composites consist of crystalline nanoinclusions, either spherical diamonds or carbon nanotubes, embedded in amorphous carbon matrices. The elastic constants of the composites were calculated and found…
Micron‐scale platelet barium titanate was synthesized using a twostep molten salt and topochemical technique. Plate‐like BaBi 4 Ti 4 O 15 was first synthesized as a precursor by molten salt synthesis. Then, Bi 3+ in the precursor was replaced by Ba 2+ and formed perovskite‐structure BaTiO 3 through a topochemical reac…
Atoms, molecules, enzymes, proteins, DNAs, RNAs, nanoparticles, microparticles, tiles, and bricks are some of the most commonly encountered building blocks in chemistry and architecture. These building blocks can be grouped into subnanometer (atoms), nanometer (molecules, enzymes, proteins, DNAs, RNAs, and nanoparticl…
We report frequency and dissipation scaling laws for doubly-clamped diamond resonators. The device lengths range from 10 microns to 19 microns corresponding to frequency and quality-factor ranges of 17 MHz to 66 MHz and 600 to 2400 respectively. We find that the resonance frequency scales as 1/L^2 confirming the valid…
The kinetics of E' centers (silicon dangling bonds) induced by 4.7eV pulsed laser irradiation in dry fused silica was investigated by in situ optical absorption spectroscopy. The stability of the defects, conditioned by reaction with mobile hydrogen of radiolytic origin, is discussed and compared to results of similar…
The photo-luminescence features of Ge-oxygen defect centers in a 100nm thick Ge-doped silica film on a pure silica substrate were investigated by looking at the emission spectra and time decay detected under synchrotron radiation excitation in the 10-300 K temperature range. This center exhibits two luminescence bands…
This work reports on high resolution photoelectron spectroscopy for the valence band of Co 2 Mn 1− x Fe x Si ( x = 0,0.5,1) excited by photons of about 8 keV energy. The measurements show good agreement with calculations of the electronic structure using the LDA + U scheme. It is shown that the high energy spectra rev…
This work reports about electronic structure calculations for the Heusler compound Co$_2$FeAl$_{1-x}$Si$_x$. Particular emphasis was put on the role of the main group element in this compound. The substitution of Al by Si leads to an increase of the number of valence electrons with increasing Si content and may be see…
Growth of vertical epitaxial Si(100) nanowires on Si(100) substrates is demonstrated (see figure) using a combination of an anodic aluminum oxide template, catalytic Au particles embedded in nanopores directly on the Si substrate by using electroless deposition, and vapor–liquid–solid growth using SiH4. HF acid treatm…
Sol-gel processing is well-known to be a powerful technique for designing materials for optical applications. Here, some recent applications of functionalized sol-gel coatings in optics are briefly reviewed. Lanthanide-doped oxide nanocrystals form a new promising class of nanophosphors allowing the easy sol-gel prepa…
In situ optical absorption spectroscopy was used to study the generation of E' centres in amorphous SiO_2 occurring by photo-induced breaking of Si-H groups under 4.7eV pulsed laser radiation. The dependence from laser intensity of the defect generation rate is consistent with a two-photon mechanism for Si-H rupture,…
Deliberations in the National Seminar held on 9-10 February, 2007 at Saha Institute of Nuclear Physics, Kolkata, INDIA