Permanent magnets
There are certain characteristics that a good magnet must have. Over the course of this century new classes of magnetic materials have been discovered which continue to improve on these key properties.
Materials Literature
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A SERS study of 1. 2. 3-benzotriazole adsorbed on silver surface
The structure of N-heterocyclic complex formed by benzotriazole on silver colloidal surface is determined with SERS technique. It is found that the adsorption on silver surface is through the triazole part of the molecule. A new chemical reaction in this system is found with the SERS technique.
Radiative and Non‐Radiative Processes of Localized Impurity Centers in Alkali Halides: KBr:Ag−
Abstract The C and A emissions in KBr:Ag − are measured in detail between 11.2 and 300 K. At 11.2 K, excitation in the peak position of the C band exhibits the C emission but it hardly produces A emission. Changing the excitation position to the higher energy side of the C band peak, the A emission is produced a littl…
On the microhardness of irradiated polycarbonate
Abstract Polycarbonate specimens were irradiated with gamma irradiation doses ranging from 2–75 Mrad. Vickers hardness number (H v ) of these specimens has been calculated. It has been found that H v decreases with irradiation dose upto 50 Mrad and thereafter it suddenly increases at 75 Mrad. This variation of H v wit…
Interpenetrating polymer networks from castor oil based polyurethanes, XI
Abstract Under different experimental conditions, various liquid polyurethanes (PU) were synthesized from castor oil and isophorone diisocyanate varying NCO/OH ratio. These polyurethanes were then subsequently interpenetrated with n‐butyl acrylate (nBA) monomer and ethylene glycol di‐methacrylate as crosslinker by rad…
Optical study of the ferroelastic phase transition in CsLiSO4
The piezooptic behaviour of CsLiSO4 corresponds to the phenomenological model of a pseudoproper ferroelastic transition in a wide temperature region of the paraelastic phase but is violated in the vicinity of the phase transition. Log-log analysis of spontaneous values of birefringence, optical indicatrix rotation and…
Structure of the cobalt(II)-"capped" porphyrin, Co(C3-Cap).3CHCl3
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure of the cobalt(II)-"capped" porphyrin, Co(C3-Cap).3CHCl3John W. Sparapany, Maxwell J. Crossley, Jack E. Baldwin, and James A. IbersCite this: J. Am. Chem. Soc. 1988, 110, 14, 4559–4564Publication Date (Print):July 1, 1988Publication History Published online1 May 200…
Kinetic ellipsometry study of the hydrogen plasma etching of hydrogenated amorphous silicon films
Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation C. Godet, B. Drevillon; Kinetic ellipsometry study of the hydrogen plasma etching of hydrogenated…
Synthesis, Crystal Structure, and Physical Properties of the Charge-Transfer Complex Bis[benzo[1,2-c:3,4-c′:5,6-c″]trithiophene]–tetrafluorotetracyanoquinodimethan, (BTT)2(TCNQF4)
Abstract The semiconductive 2:1 charge-transfer complex between benzo[1,2-c:3,4-c′:5,6-c″]trithiophene and 2,2′-(2,3,5,6-tetrafluoro-2,5-cyclohexadiene-1,4-diylidene)bis[propanedinitrile], (BTT)2(TCNQF4), crystallizes in the monoclinic system, space group P21⁄c, with the following cell constants: a=8.893(2) Å, b=10.58…
A Note on the Thermal Conductivity of Filled Polymers
The thermal conductivity of a composite formed by sand fillers embedded in a poly ethylene matrix is studied experimentally. Results show a region of low particle content, where the conductivity is predicted by Maxwell-Eucken equation. Only at very high par ticle content, the filler tends to form agglomerates and cond…
Quantitative XRD Studies of ZnAl2O4(Spinel) Synthesized by Sol-Gel and Powder Methods
ZnAl{sub 2}O{sub 4} spinel was prepared by both the sol-gel method and by the solid-state reaction technique. Physical properties of the product obtained by the two methods are compared. Sol-gel-derived ZnAl{sub 2}O{sub 4} showed evidence of crystals at as low as 264{degree}C. Quantitative x-ray diffraction (XRD) meth…
Recent developments in the synthesis and functionalization of conducting poly(thiophenes)
Abstract The mechanism of the electropolymerization of thiophene derivatives has been investigated by varying the electrosynthesis conditions and the monomer structure. The results of these analyses led to the definition of optimized electrosynthesis conditions allowing the control of the electrical and electrochemica…
Phase transitions and ferroelectric properties of lead ferroniobate
The purpose of this work was to determined the value of spontaneous polarization accurately and to obtain additional information about phase transitions in perovskite lead ferroniobate, in particular, about the effect on the electric characteristics of the ceramic. The measured values of the spontaneous polarization o…
Morphologies and regimes of growth of polybutene crystals in phase II
Abstract The growth rates of two poly(1‐butene) with different molecular weights have been deduced from microscopic observations and the corresponding morphologies have been described. In both polymers two changes in the growth regime are observed and interpreted according to Hoffman's kinetic theory of polymer crysta…
Influence of the microscopic shape anisotropy of the micelles on the pitch in a cholesteric lyotropic liquid crystal
The influence of the microscopic shape anisotropy of the micelles on the pitch of a cholesteric lyotropic liquid crystal is investigated by x-ray diffraction and optical techniques. The mixture studied is potassium laurate, decanol, water, and brucine sulfate. The relative molar concentration of the brucine sulfate is…
Syntheses and Properties of Dipyridylnorbornadienes
Abstract 2,3-Dipyridylnorbornadienes were prepared using the Diels–Alder reaction of the HBF4 salts of dipyridylacetylenes with cyclopentadiene. Their absorptions extend to 380 nm and are red-shifted in an acidic media. They underwent photocyclization to give quadricyclanes which reverted to norbornadienes upon heatin…
Microwave study of the soft ferroelectric mode in Sn2P2S6crystals
This paper presents the results of the investigation of dielectric dispersion in semiconductive ferroelectric Sn2P2S6 crystals over the frequency range 1 kHz to 78.5 GHz. The main dielectric dispersion in Sn2P2S6 is caused by the soft ferroelectric Bu mode and in the vicinity of the Curie point it occurs in the millim…
Serotonin and β‐thromboglobulin release reaction from platelet as triggered by interaction with polypeptide derivatives
The effect of wettability of 14 polypeptide derivatives upon adhesion and activation of platelets was investigated with reference to release reactions from adhered platelets, using radioisotope labeling and radioimmunoassay method. The serotonin release was more significant from platelets adhered to polymer materials…
Experimental measurement of solutal layers in unidirectional solidification
An experimental study to evaluate and characterize the effects of inverted density layers during the directional solidification of metal alloys is described. The temporal history of the inverted density layers in front of a dendritic interface for directionally solidified ammonium-chloride 72-wt-% water is presented b…
Electron spectroscopic imaging studies on polyethylene, chain‐folded and extended‐chain crystals
Abstract Discrimination of elastically and inelastically scattered electrons in transmission electron microscopy (TEM) yields electron micrographs with enhanced and specific contrast. Highly resolved micrographs can be obtained in which the contrast reflects the local concentrations of specific elements. In the presen…