Materials Literature
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The addition of oxygen in Ca0.5Sr0.5Ga2S4:Ce phosphor was found to nearly double the luminance and to blue shift the emission spectrum of the Ce+3 4f–5d transition. X-ray photoelectron spectroscopy (XPS) analysis was used to investigate the local chemistry of the Ce+3 luminescent center in the undoped and oxygen-doped…
Passivation of the zirconium surface and stability of anodic oxide film were investigated as a function of surface preparation. The mechanically polished surface appeared to be more reactive toward oxide thickening than the etched one, as revealed by impedance measurements. Oxide film formed on the etched electrode di…
We consider the effects of the application of electric and magnetic fields to a homogeneously aligned nematic liquid crystal which lies between parallel plates. The average alignment of the fluid molecules is known as the director and it is set parallel to the top and bottom bounding surfaces. At a critical field stre…
The low-temperature form of K3Sm(PO4)2 crystallizes in the monoclinic system [a = 7.4347(5) Å, b = 5.6270(5) Å, c = 9.4919(5) Å, β = 90.870(6)°, Z = 2, space group P21/m]. The structure has been determined using 1263 independent reflections (R = 0.045, Rw = 0.11) and is found to be of the glaserite type. The Raman and…
Abstract Large and well-formed crystals of barium chlorapatite [Ba5Cl(PO4)3] were grown for the first time from a sodium chloride flux. The solubility of Ba5Cl(PO4)3 in NaCl increased with increasing temperature, reaching about 1.9 mol% solubility at 1100 °C. The crystal growth of Ba5Cl(PO4)3 was conducted by heating…
In this paper the over-thirty-years history of space applications of shape memory alloys (SMA) is summarized. Our experience is illustrated by detailed examples, such as the first launch of TiNi to an Earth orbit in 1982, when thermomechanical pipe couplings on the orbital station Salyut-7 were tested for their hermet…
The disorder in ion motion in a LaF 3 superionic conductor with tysonite structure is determined from NMR spectra. The method is sensitive to dynamic effects with correlation times of 5×10 −3 < τ <10 −6 s. Within the 260–400-K interval, ion movement is observed only on one of the sublattices (F 1 ), and it exhibits a…
The numerical algorithm for cap generation [1] is further developed. the cap unfolding method proposed in ref. [2] is used. Some aspects of the cap unfolding onto the honeycomb lattice [3] are also considered. Topological invariants of the cap structures are used to eliminate the duplicate structures. the list of all…
The development of crazes in polycarbonate was investigated with the method of ultra-small-angle X-ray scattering (USAXS) of synchrotron radiation. Measurements at different temperatures and with different draw rates were carried out. The two-dimensional scattering patterns were analyzed by means of a fibrillar model…
We report on measurements of the transmitted depolarized light intensity and on small-angle neutron scattering (SANS) measurements on a compositionally asymmetric poly(ethylene propylene)-poly(dimethylsiloxane) diblock copolymer studied in the bulk. SANS measurements were made both on isotropic and on shear oriented s…
The development of blowing agents that exhibit lower thermal conductivity, shorter atmospheric lifetime, and less adverse effects on the atmosphere is an urgent issue. We investigated three fluorinated ethers as blowing agent alternatives [2,2,2-trifluoroethyl difluoromethyl ether (HFE-254mf), 2,2,3,3,3-pentafluoropro…
This article presents the piezoelectric and mechanical properties of bismuth layer-structured ferroelectrics (BLSF)-based BaBi 4 Ti 4 O 15 ceramics incorporating Ba 4 Ti 13 O 30 . The ceramic compositions, (1- x )BaBi 4 Ti 4 O 15 – x Ba 4 Ti 13 O 30 with x =0–100 vol%, are obtained through solid-state reaction process…
The specific heat of a single crystal of the layered perovskite La[sub 1.2]Sr[sub 1.8]Mn[sub 2]O[sub 7] has been measured for 83[lt]T[lt]290 hthinsp;K. A high, narrow peak associated with the ferromagnetic ordering of the Mn[sup 3+]-Mn[sup 4+] ions is observed to have a maximum at T[sub c]=115.57 hthinsp;K, in agreeme…
We report here an investigation of amphibole synthesis within the ternary system Ca 2 Mg 5 Si 8 O 22 (OH) 2 - NaCa 2 Mg 4 Al 3 Si 6 O 22 (OH) 2 -Mg 7 Si 8 O 22 (OH) 2 (= TR-PG-MC) to define better the limits of solid solution for amphiboles formed along and near the join tremolite-pargasite. Hydrothermal syntheses wer…
The production of molecular hydrogen in the radiolysis of high-density polyethylene by γ rays and heavy ion beams has been investigated. Only the slightest increase in the radiation chemical yield of 3.1 molecules/100 eV was found from γ rays to protons of 5−15 MeV. A gradual increase in yield was observed on further…
We show that the drift velocity of the cholesteric fingers of the second species in ac electric field strongly depends on the conductivity of the liquid crystal chosen and exponentially vanishes above a cutoff frequency we found to be equal (within a numerical factor close to 1) to the charge relaxation frequency of t…
Bi 2 O 3 -based ZnO varistor materials were prepared by 2.45 GHz microwave, 24 GHz millimeter-wave or conventional sintering processes. Both millimeter-wave and microwave sintering processes are superior to the conventional sintering process for densifying Bi 2 O 3 -based ZnO materials. Moreover, the millimeter-wave s…
Behaviors of pretilt angles of liquid crystal (LC) cells were examined using polyimide (PI) films containing fluorine atoms by exposure to ultraviolet light (UV). Using a single obliquely polarized UV exposure, we obtained unidirectional LC alignment with any desired pretilt angles from 0° up to 90°. The pretilt angle…
This work deals with the AC electrical properties measurements under large strain of composites strongly contrasted in the viewpoint of their electrical and mechanical properties. First, the possibility to model a strongly heterogeneous material (from the viewpoint of electrical properties) using an improvement of a R…
The specific heat of a polycrystalline sample of MnO was measured from $T\ensuremath{\approx}1\mathrm{K}$ to $T\ensuremath{\approx}400\mathrm{K}$ using two different experimental apparatuses at zero applied pressure. Features revealed by the data include a hyperfine contribution due to the Mn nuclei, a ${T}^{2}$ tempe…