Materials Literature
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We report measurements of structural phase transition of four parent compounds $R\text{FeAsO}$ ($R=\text{La}$, Sm, Gd, and Tb) by means of low-temperature x-ray diffraction (XRD). Magnetic transition temperatures associated with Fe ions $({T}_{N1})$ are also determined from the temperature dependence of resistivity. A…
The Hall effect and resistivity of the carrier doped magnetic semiconductor Fe$_{1-x}$Co$_x$S$_2$ were measured for $0\le x \le 0.16$, temperatures between 0.05 and 300 K, and fields of up to 9 T. Our Hall data indicate electron charge carriers with a density of only 10 to 30% of the Co density of our crystals. Despit…
We have observed a quadratic x-ray magneto-optical effect in near-normal incidence reflection at the M-edges of iron. The effect appears as the magnetically induced rotation of ca. 0.1$ degrees of the polarization plane of linearly polarized x-ray radiation upon reflection. A comparison of the measured rotation spectr…
Despite the growing interest of quantum dots (QDs) in biological applications, there are many concerns regarding the potential accumulation and toxic effects of Cd-containing QDs in animals and humans. Zinc oxide QDs are promising alternatives for diagnosis and imaging but their aqueous instability has markedly limite…
Spray processable blue electrochromic polymers with strictly alternating “donor-acceptor” copolymers are reported that exhibit saturated blue neutral states, highly transmissive oxidized states, excellent optical contrasts, fast switching times, and long-term redox switching stability. In addition, an alkylester-funct…
We report the X-ray attenuation property of dendrimer-entrapped gold nanoparticles (Au DENPs) that could be used as a computed tomography (CT) contrast agent. Amine-terminated generation 5 (G5.NH 2 ) poly(amidoamine) dendrimers were used as templates to complex AuCl 4 − ions for subsequent reductive formation of Au DE…
Abstract Biological photonic systems composed of anhydrous guanine crystals evolved separately in several taxonomic groups. Here, two such systems found in fish and spiders, both of which make use of anhydrous guanine crystal plates to produce structural colors, are examined. Measurements of the photonic‐crystal struc…
We report the synthesis of novel diphenylalanine/cobalt(II,III) oxide (Co(3)O(4)) composite nanowires by peptide self-assembly. Peptide nanowires were prepared by treating amorphous diphenylalanine film with aniline vapor at an elevated temperature. They were hybridized with Co(3)O(4) nanocrystals through the reductio…
Space charge formation in polymeric materials can cause some serious concern for design engineers as the electric field may severely be distorted, leading to part of the material being overstressed. At the worst, this may result in material degradation and possibly premature failure. It is therefore important to under…
We have conducted an experimental and theoretical study on first- and second-order Raman scattering of zinc blende and wurtzite ZnS. Based on the calculated phonon band structure, phonon density of states, and symmetry selection rules, we have clearly identified for the first time the origins of these vibration modes…
Abstract Recently a significant figure‐of‐merit ( ZT ) improvement in the most‐studied existing thermoelectric materials has been achieved by creating nanograins and nanostructures in the grains using the combination of high‐energy ball milling and a direct‐current‐induced hot‐press process. Thermoelectric transport m…
We report a non-Pb piezoelectric ceramic system $\mathrm{Ba}({\mathrm{Ti}}_{0.8}{\mathrm{Zr}}_{0.2}){\mathrm{O}}_{3}\mathrm{\text{\ensuremath{-}}}({\mathrm{Ba}}_{0.7}{\mathrm{Ca}}_{0.3}){\mathrm{TiO}}_{3}$ which shows a surprisingly high piezoelectric coefficient of ${d}_{33}\ensuremath{\sim}620\text{ }\text{ }\mathrm…
The governing reaction mechanisms, and the electrode material compositions and structures, that controls the efficiency of the solid oxide fuel cells (SOFC) and solid oxide electrolysis cells (SOEC) need to be identified and well-understood for significant technological improvements. Our study on the oxygen electrodes…
Stable field emission currents and low fluctuations are important feasibility requirements for the application of materials in field emission devices and displays, more than the low turn on fields that are generally considered. The current stability and current fluctuations of field emitted electrons from ZnO nanostru…
From the dried roots of Campylotropis hirtella (Franch.) Schindl., five novel isoflavonoids, 3( S)-7,2',4'-trihydroxy-5,5'-dimethoxy-6-(3-methylbut-2-enyl)-isoflavan ( 1), 3( S)-2',4'-dihydroxy-5,5'-dimethoxy-(6'',6''-dimethylpyrano)-(2'',3'':7,6)-isoflavan ( 2), 3( R)-5,4'-dihydroxy-2'-methoxy-3'-(3-methylbut-2-enyl)…
Octafunctionalised dibenzochrysenes are prepared in order to study the liquid crystalline properties that have chiral and achiral peripheral aliphatic chains. The syntheses of dibenzochrysene derivatives are achieved by a conventional method that has been developed recently. The achiral derivatives that have long peri…
The X-ray absorption near edge structure (XANES) and X-ray excited optical luminescence (XEOL) of a set of photoluminescent rare earth (RE) (Tb, Ce) doped silicon oxide (SiOx) thin films, having compositions ranging from O-rich (32% Si) to Si-rich (36% Si), were analyzed at the Si and O K-edges. The results show that…
Polycrystalline Mo(3)Sb(7-x)Te(x) samples with nominal Te concentrations of x=0.0, 0.3, 1.0, 1.6 and 2.2 have been synthesized by a powder metallurgical route. High temperature thermoelectric properties measurements including thermopower (300-900 K), electrical resistivity (300-800 K) and thermal conductivity (300-100…
Abstract By studying chitosan interactions with poly(styrene sulfonate) anions, a procedure that yields chitosan‐based non‐stoichiometric polyelectrolyte complexes soluble in neutral media has been developed. The elaborated strategy of the complex formation depended on the peculiar order of mixing the polyelectrolyte…
Surface acoustic wave (SAW) propagation properties in relaxor-based 0.67Pb(Mg(13)Nb(23))O(3)-0.33PbTiO(3) (PMN-33%PT) ferroelectric single crystals poled along [111](c) has been analyzed theoretically. We found that the X-cut PMN-33%PT has lower phase velocity and higher electromechanical coupling coefficient compared…