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Magnetic Properties of Co–Sn Substituted Barium-Ferrite Particles for Magnetic Recording

F. L. Wei、Mai Lu、Zhengchun Yang1998-10-01physica status solidi (a)

In order to improve the margin for operating temperature changes and to achieve high recording performance, Co–Sn substituted Ba-ferrite particles were investigated. It was found that BaFe12—2xCoxSnxO19 particles with x = 1.10 to 1.40 not only have a coercivity suitable for magnetic recording, but also have a very low…

Magnetic properties of thin filmsMagnetic Properties and Synthesis of FerritesMagnetic Properties and Applications

Diffuse reflections and the symmetry of vesuvianite

Lee A. Groat、F. C. Hawthorne1998-10-01Phase Transitions

Vesuvianite is a common rock-forming silicate mineral with the general chemical formula X19Y13Z18T0.5O68W10 , where X = Ca, Na, Ln, Pb, Sb; Y= Al, Mg, Fe, Ti, Mn, Cu, Zn; Z = Si; T= B; W= (O, OH, F). Vesuvianite is ideally tetragonal with space group P4/nnc, but many samples show physical properties that indicate devi…

Geological and Geochemical AnalysisClay minerals and soil interactionsX-ray Diffraction in Crystallography

Pyrolytic conversion of precursors prepared in Ti(NMe2)4-diamine systems

Seiichi Koyama、Daisuke Lizuka、Yoshiyuki Sugahara 等 4 位作者1998-10-01Applied Organometallic Chemistry

Precursors possessing Ti–N bonds were prepared by the reactions between Ti(NMe2)4 and each of three diamines H2NCH2CH2NH2, Me(H)NCH2CH2N(H)Me, HN(CH2CH2)2NH (Ti(NMe2)4:diamine = 1:2), and were converted into ceramics by pyrolysis. The reactions with H2NCH2CH2NH2 and HN(CH2CH2)2NH led to the formation of insoluble soli…

Advanced ceramic materials synthesisMXene and MAX Phase MaterialsAdvanced materials and composites

Strain-stabilized precursor clusters in potassium thiocyanate

O. Blaschko、W. Schranz、Martin Fally 等 5 位作者1998-10-01Physical review. B, Condensed matter

We present refined diffuse neutron scattering measurements performed in the long-range-ordered phase of potassium thiocyanate $(T<{T}_{c}).$ The analysis of the data yields that the diffuse scattering is due to the presence of order-parameter fluctuations that appear as a precursor to the order-disorder phase trans…

Material Dynamics and PropertiesSpectroscopy and Quantum Chemical StudiesSolid-state spectroscopy and crystallography

ITC study of Ga+-, Ge2+-, and Sn2+-doped alkali halides

B. Macalik、Máximo Siu Li、S. Zazubovich1998-10-01Radiation effects and defects in solids

The search of the off-centre displacement of an impourity iron from the crystal lattice site in the ground electronic state has been performed by the ionic thermocurrent (ITC) method for Ga+, Ge2+ v− c, and Sn2+ v− c centres in some alkali halides. No ITC peak has been found at T>5 K for Ga+ ions. One ITC peak at the…

Zeolite Catalysis and SynthesisSolid-state spectroscopy and crystallographyThermal Expansion and Ionic Conductivity

Investigation of boundaries and structures in dissimilar metal welds

Tracy W. Nelson、John C. Lippold、M.J. Mills1998-10-01Science and Technology of Welding & Joining

Cracking, or disbonding, along the fusion boundary in dissimilar metal welds has been a persistent problem, particularly in applications where austenitic alloys are clad on to structural steels for corrosion protection. Many failures in dissimilar metal welds occur as a result of cracking along a boundary that runs pa…

Fusion materials and technologiesHydrogen embrittlement and corrosion behaviors in metalsHigh Temperature Alloys and Creep

Evaluation of several methods for determining the potassium content in diverse plant materials

Ch. Srinivasa Rao、A. Subba Rao、P. N. Takkar1998-10-01Communications in Soil Science and Plant Analysis

Different plant analysis methods including varied incubation times with 0.5N and IN hydrochloric acid (HCl), diacid [nitric (HNO3) and perchloric (HClO4) acids], triacid [HNO3, sulfuric acid (H2SO4) and HClO4], H2SO4+hydrogen peroxide (H2O2) (Wolf method), and 0.5N and lN ammonium acetate (NH4OAc) were evaluated for m…

Plant Micronutrient Interactions and EffectsClay minerals and soil interactionsAgricultural Science and Fertilization

Precursors in lead phosphate-type ferroelastics: Diffuse X-ray scattering, group theory and modelling

Carsten Paulmann、U. Bismayer、M. I. Aroyo1998-10-01Phase Transitions

A chain-adapted symmetry-mode analysis is presented for the symmetry change R 3 m > C12/c1 in ferroelastic lead phosphate. The primary and the secondary modes are derived for all relevant Wyckoff positions. The splitting schemes of the orbits and the patterns of the displacive modes are compatible with experimental di…

Ferroelectric and Piezoelectric MaterialsPhotorefractive and Nonlinear OpticsSolid-state spectroscopy and crystallography

Blue-Light Emission from Nanocrystalline La 0.5 Na 0.5 TiO 3

Weifeng Zhang、Xingtang Zhang、Zhen Yin 等 6 位作者1998-10-01Chinese Physics Letters

Nanocrystalline La 0.5 Na 0.5 TiO 3 powders were prepared by the stearic acid-gel method, and the grain sizes could be controlled by varying annealing temperatures. The sizes were determined to be from 14 to 50 nm using Scherrer's formula. A very strong blue-light emission band around 480 nm was clearly observed in th…

Luminescence Properties of Advanced MaterialsFerroelectric and Piezoelectric MaterialsElectronic and Structural Properties of Oxides

The cholesteric-smectic A transition

L. Benguigui1998-10-01Liquid Crystals

Instead of studying the cholesteric-smectic A transition from the analogy with superconductors, we present a direct investigation of the properties of this transition. The transition is of first order and a very simple relationship between the four basic lengths (correlation length, penetration length, layer spacing o…

Liquid Crystal Research AdvancementsPlant Reproductive BiologyMolecular spectroscopy and chirality

Orientation of Lyotropic and Thermotropic Liquid Crystals on Plasma-Treated Fluorinated Surfaces

Noushine Shahidzadeh、A. Merdas、W. Urbach 等 6 位作者1998-10-01Langmuir

A carbon tetrafluoride plasma discharge using a grafting mechanism and very short treatment times (a few milliseconds to a few seconds) was used to obtain high-quality reproducible surfaces that permit the homeotropic alignment of lyotropic as well as thermotropic liquid crystals. The intermolecular interactions betwe…

Advanced Chemical Physics StudiesLiquid Crystal Research AdvancementsPorphyrin and Phthalocyanine Chemistry

Study of Optical Switching and Reorientation in Liquid Crystals of Homologous Series of 4-n-butyl-4′-n-alkoxyazobenzenes

V. A. Grozhik、Helen F. Gleeson、Svetlana Serak 等 5 位作者1998-10-01Molecular crystals and liquid crystals science technology. Section A, Molecular crystals and liquid crystals/Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals

Two mechanisms of optical response in liquid crystals (LC) of homologous series 4-n-butyl-4′-n-alkoxyazobenzenes (BAAB), namely the photochemical phase transition and reorientation in bulk of LC are considered. The temporal parameters of writing (Ar+ laser) and erasing (He-Ne laser) of information on BAAB on the basis…

Liquid Crystal Research AdvancementsPhotochemistry and Electron Transfer StudiesMolecular spectroscopy and chirality

Thermische Zersetzung und Lösungskalorimetrie von Ammoniumeuropiumchloriden / Thermal Decomposition and Solution Calorimetry of Ammonium Europium Chlorides

C. Hennig、H. Oppermann、A. Blonska1998-10-01Zeitschrift für Naturforschung B

Abstract The thermal decomposition equilibria of ammonium europium chlorides (NH 4 ) 3 EuCl 6 , (NH 4 ) 2 EuCl 5 and NH 4 Eu 2 Cl 7 have been investigated by total pressure measurements in a membrane zero manometer. The thermodynamic data of these solid phases have been derived from the decomposition functions. The st…

Chemical and Physical Properties in Aqueous SolutionsThermal and Kinetic AnalysisChemical Thermodynamics and Molecular Structure

Korrosionsbeständigkeit metallisch und organisch vorveredelter Stahlfeinbleche in der Freibewitterung

Bernd Schuhmacher、Dietrich Wolfhard1998-10-01Materials and Corrosion

In einer umfassenden Untersuchung werden die besonders günstigen Korrosionsschutzeigenschaften Galfan-schmelztauchveredelter Feinbleche sowohl im unlackierten als auch im bandbeschichteten Zustand aufgezeigt. An fünf unterschiedlichen Bewitterungsorten wurden feuerverzinkte und Galfan-schmelztauchveredelte Prüfbleche…

Mechanical Behavior of CompositesCorrosion Behavior and InhibitionConcrete Corrosion and Durability

Stationary hopping photoconduction among multiply charged impurity atoms in crystals

N. A. Poklonskii、Sergey Lopatin1998-10-01Physics of the Solid State

A derivation of the equation for the hopping current of electrons and holes (electron vacancies) among impurities of a single species in three charge states [(−1), (0), and (+1)] is given in the continuum approximation. The screening length of an electrostatic field and the diffusion length of charge carriers are calc…

Photorefractive and Nonlinear OpticsSolid-state spectroscopy and crystallographyElectron and X-Ray Spectroscopy Techniques

Viscosity Measurements on Molten Salts with an Oscillating Cup Viscometer: Viscosity of Molten KNO3 and NaCl

Dumitru Tolbaru、Rodica Borcan、S. Zuca1998-10-01Berichte der Bunsengesellschaft für physikalische Chemie

Abstract An oscillating cup viscometer interfaced to an automatic data acquisition and processing system (computer, interface, software) was built for viscosity measurements in molten salts below 1400 K. In order to avoid the “meniscus effect”, the main source of errors of the method, the measurements were carried out…

Solidification and crystal growth phenomenaMetallurgical Processes and Thermodynamics

Equilibrium of native point defects in tin dioxide

K. P. Bogdanov、D. Ts. Dimitrov、O. F. Lutskaya 等 4 位作者1998-10-01Semiconductors

A model of electrically active and neutral native point defects in SnO2 is developed. Thermodynamic analysis of the equilibrium of the native point defects makes it possible to construct the phase diagram $$P_{O_2 } - T - x$$ of lead dioxide. The contradiction between n-type monopolar conductivity and the two-sided ho…

Transition Metal Oxide Nanomaterials

Tin‐zinc plating

Edward Budman、D.W. Stevens1998-10-01Anti-Corrosion Methods and Materials

There is a continuing desire to obtain sacrificial plated coatings that provide ever higher standards of protection. This paper looks at alternatives to cadmium dye to its toxic and carcinogenic characteristics. Alloy combinations with zinc are considered. It concludes that tin‐zinc alloy plating gives excellent corro…

Corrosion Behavior and Inhibition

Charge carrier transport in polyimides based on 9,10-bis(p-aminophenyl)anthracene

Alek R. Tameev、Aleksey A. Kozlov、А. В. Ванников 等 6 位作者1998-10-01Polymer International

Transient currents were measured by the time-of-flight technique in films of aromatic polyimides based on 9,10-bis(p-aminophenyl)anthracene and a series of diimide fragments. The electric field and temperature dependences of the hole and electron drift mobilities were detected. In amorphous films of the soluble polyim…

Organic Electronics and PhotovoltaicsConducting polymers and applicationsSynthesis and properties of polymers

Origin of lower Eocene palygorskite clays in the Côte d'Ivoire-Ghana Transform Margin, eastern equatorial Atlantic

Thomas Pletsch1998-10-01OpenAlex

Palygorskite was identified in lower Eocene clays and porcellanites in Holes 959D, 960A, 960C, and 961A; in upper Albian to Cenomanian clays with chert in Hole 962B; and in undated clays in Holes 962B and 962C of Ocean Drilling Program Leg 159. Palygorskite is particularly abundant in lower Eocene bluish claystones of…

Clay minerals and soil interactionsGeological and Geophysical Studies WorldwideGeotechnical and construction materials studies