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。
La 0.7 Sr 0.3 MnO 3 / Sm 0.7 Sr 0.3 MnO 3 (LSMO/SSMO) nanocomposites were prepared by a sol–gel coating method. The microstructural, magnetic, and transport properties of the composites were investigated. A significant enhancement in magnetoresistance (MR) under an applied field of 5 T is observed from low temperature…
The substitution of Co for Mn in La0.67Sr0.33Mn1−xCoxO3 lowers the Curie temperature TC and the metal–insulator transition temperature TMI, accompanying the increase of the resistivity due to the weakening of the double-exchange interaction. The difference value between the TC and the TMI increases with Co substitutio…
Cross-linked epoxy network films were cast onto silicon wafers with a variety of surface treatments. X-ray reflectivity was used to characterize their electron density and thermal expansion in the rubbery state. A transition from “bulk” to “confined” expansion occurs in the range of 200−400 Å, where thinner films exhi…
Polycrystalline samples of Fe1−xCr2S4(x=0.0, 0.04, 0.08) have been studied with x-ray and neutron powder diffraction, Mössbauer spectroscopy, magnetization, and magnetoresitance (MR) measurements. Neutron diffraction patterns were obtained at various temperature ranges from 10 K to room temperature. Neutron diffractio…
Enzymatic degradability has been investigated for a series of bacterial poly(3-hydroxybutyrate-co-3-hydroxypropionate)s (P(3HB-co-3HP)s) with 3-hydroxypropionate (3HP) unit contents from 11 to 86 mol % as well as poly(3-hydroxybutyrate) (P(3HB)) and chemosynthesized poly(3-hydroxypropionate) (P(3HP)). The behavior of…
We report results of experimental investigations of the luminescent properties of two different conjugated polymers in which we embedded nanocrystals of Al2O3, Y2O3, ZnO, and SnSbO. The dielectric nanocrystals result in a blueshifting and broadening of luminescence spectra of poly(p-phenylene vinylene) with a simultan…
LaFe 13−x Si x compounds with x=2.4, 2.6, and 2.8 have been carefully prepared and characterized. X-ray powder diffraction patterns confirm that the samples crystallize in a single NaZn13-type phase. Magnetic measurements were carried out in a SQUID magnetometer. The Curie temperature Tc of LaFe13−xSix samples decreas…
Thin films of highly anisotropic rare earth intermetallic compounds increasingly come into the focus of interest for application in magnetic miniature devices. We prepared hard magnetic SmCo and NdFeB films by pulsed laser deposition and investigated the influence of rare-earth content on phase formation, microstructu…
The microwave properties of Z type Ba hexagonal ferrites with uniaxial anisotropy can be controlled over a wide range by choice of an appropriate mixture of Zn, Ni, and Co as divalent species. Using unmagnetized powders of these ferrites, the microwave permeability spectra were taken in a swept frequency mode in the t…
A general sum rule has been established recently, bounding the integral of the gyromagnetic losses weighted by the frequency, by the square of the saturation magnetization [O. Acher and A. L. Adenot, Phys. Rev. B 62, 11324 (2000)]. This rule has been established for soft materials with internal anisotropy fields small…
We have prepared homogeneous SmCox (x=5–26) sputtered thin films of thickness 500 nm with excess Co compared to SmCo5. The purpose is to determine how any spring exchange incorporated by the excess Co improves the energy product. Films are subjected to a 30 s or 20 min anneal to crystallize the Sm–Co. In the case of b…
Abstract Poly(methyl methacrylate) (PMMA) was γ‐irradiated (5–20 kGy) by a 137 Cs source at room temperature in air. The changes in the molecular structure attributed to γ‐irradiation were studied by mechanical testing (flexure and hardness), size‐exclusion chromatography, differential scanning calorimetry, thermal gr…
The photoluminescence properties of ZnO/ZnMgO multiquantum wells have been investigated by continuous and time-resolved photoluminescence spectra at various temperatures. Strong first-order and second-order longitudinal optical (LO)-phonon replicas were observed in the emission spectra. Both the zero-phonon emission a…
Soft, high moment materials are crucial for the magnetic data recording industry in applications such as write poles and soft underlayers. Ever increasing areal densities have pushed the requirements for materials exhibiting saturation magnetizations above 2 T. In this work we investigate nanocrystalline FeCoB which e…
Six selenium variants of BEDT-TTF have been successfully synthesized by a newly developed synthetic method that involves a combination of two key reactions for the construction of two kinds of heterocyclic rings: the first is a one-pot formation of 1,3-dichalcogenole-2-chalcogenones from a common starting material, TH…
Polycrystalline Ni–Mn–Ga thin films have been deposited by the pulsed laser deposition (PLD) technique, using slices of a Ni–Mn–Ga single crystal as targets and onto Si (100) substrates at temperatures ranging from 673 K up to 973 K. Off-stoichiometry thin films were deposited at a base pressure of 1×10−6 Torr or in a…
Electron energy-loss (EEL) spectroscopy performed near dislocation cores is one of the few experimental techniques that can yield valuable information about the electronic levels associated with dislocations. In this study, we present experimental observations of low-loss EEL spectroscopy acquired on grain boundary di…
Pb 1−x Ca x TiO 3 (0.10⩽x⩽0.40) thin films on Pt/Ti/SiO2/Si(100) substrates were prepared by the soft solution process and their characteristics were investigated as a function of the calcium content (x). The structural modifications in the films were studied using x-ray diffraction and micro-Raman scattering techniqu…
Ni–Zn ferrite films were prepared by spin-spray ferrite plating method at 90 °C on glass substrates from a reaction solution of FeCl2(+FeCl3)+NiCl2+ZnCl2 and an oxidizing solution of NaNO2+CH3COONH4. The complex permeability μ=μ′−iμ″ values of the as-plated films were measured at frequencies up to 3 GHz. The Ni0.28Zn0…
We derive a rigorous f-sum rule for the spin conductivity D(ω), valid in the paramagnetic regime of any itinerant system with nearest-neighbor hopping, assuming only that the potential energy conserves the total spin at each site. Two such itinerant systems are the double-exchange and Hubbard models. According to the…