Materials Literature
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Abstract Results obtained by differential scanning calorimetry have been used to develop a macro‐kinetic model for the crystallization behavior of semicrystalline polymeric materials. Our model, which takes into account the effects of induction time, final degree of crystallinity and secondary crystallization, describ…
The compounds of the Sr 2 Nb 2 O 7 (SNO) family are suitable for use as ferroelectric materials for ferroelectric memory field effect transistors (FETs), because these substances have a low dielectric constant, low coercive field and high heat-resistance. In this study, we succeeded in preparing Sr 2 (Ta,Nb) 2 O 7 (ST…
The lifetime and degradation mechanism of the multilayer ceramic actuator (MCA) were studied. The effects of temperature, humidity and load on the lifetime of the MCA under high DC or 50 Hz unipolar AC voltages are discussed. The logarithm of the lifetime had a linear relationship with the logarithm of the electric fi…
A series of side chain dendritic polymers (SCDP) was produced by copolymerization of dendritic diols of the second, third, and fourth generation with four different semirigid and flexible diisocyanates. The polymerization reactions were conducted both in solution and in bulk. The degree of polymerization and molecular…
Canonical loops of protein inhibitors of serine proteinases occur in proteins having completely different folds. In this article, conformations of the loops have been analyzed for inhibitors belonging to 10 structurally different families. Using deviation in Calpha-Calpha distances as a criterion for loop similarity,…
The four-membered β-butyrolactone (BL) was polymerized using a ring-opening polymerization reaction with lipase as a catalyst at a temperature between 60 and 100 °C to yield the corresponding cyclic and linear poly(3-hydroxybutyrate)s [P(3HB)] with weight-average molecular weights of up to 7300. Among the tested lipas…
Single crystals of γ-Ti-54.5at.% Al with two different orientations have been deformed between room temperature and 1223K. Both exhibit a yield stress anomaly. The operating slip systems and dislocation structure have been determined by optical and transmission electron microscopy, and the dissociation of the [011] su…
The influence of the microstructure evolution on electrical properties as a parameter of the firing temperature was studied for materials in the BaTiO 3 (BT)–MgO–Ln 2 O 3 (Ln=Ho and Dy) system. The sintering behavior and the formation of the core-shell structure were dependent on the kind of doped rare earth elements.…
The magnetic properties of the ball-milled nanocrystalline fcc phase of FeRh alloys are reported and discussed. The observed features (maximum of ac and zero-field cooling susceptibility at a temperature ${T}_{\mathrm{max}}$ weakly dependent on the frequency and on the applied field) suggest a progressive blocking of…
In this paper, the feasibility of automatic least-squares refinement of a Monte Carlo model of a disordered structure by quantitative comparison of its calculated diffraction pattern with observed diffuse scattering data is demonstrated. At each stage of the refinement, the goodness-of fit parameter χ2 is used as a qu…
Abstract Secondary electron imaging is not possible in the variable pressure scanning electron microscope because the mean free path of the secondaries in the gas is too short to permit them to reach the detector. This paper therefore investigates an alternative strategy for producing an image containing significant a…
Wetting and reactions between molten Al and silicate substrates (particularly mullite) are studied to determine both how substrate tensity and p (O 2 ) influence wetting behavior, reaction rates, composition, and reaction product microstructure and what key steps control penetration kinetics. Guidelines are provided f…
The crystal structure of a Zn-Mg-Y hexagonal phase, considered to be related to that of the quasicrystalline phase, has been determined by single-crystal X-ray diffraction. The atomic model, refined to a final R value of 0.027, has the composition Zn65.22Mg27.92Y6.86 and 92 atoms in a unit cell with lattice constants…
By spatially resolved single-wavelength ellipsometry, we investigate the spreading on a solid substrate of low molecular weight trimethyl-terminated poly(dimethylsiloxane) droplets. Especially, we focus our study on the dependence of the diffusion coefficient of the first molecular layer on the substrate surface energ…
Re(O)Cl(3)(PPh(3))(2), 1, and Re(O)Cl(3)(OPPh(3))(Me(2)S), 2, catalyze the oxidation of thiols to disulfides with sulfoxides under mild conditions. Catalyst 1 exhibits an induction period which features PPh(3) oxidation to OPPh(3) prior to disulfide formation. This lag is absent when 2 is the catalyst precursor. Other…
Phase boundary and domain structure in relaxor ferroelectrics Pb(Zn 1/3 Nb 2/3 )O 3 /9%PbTiO 3 were observed using a (111) plate under a polarization microscope. The dielectric constant was measured simultaneously to determine exact transition temperatures and to connect the dielectric behavior with phase boundary mov…
Chiral polyaniline colloids have been generated via the electrohydrodynamic polymerization of aniline in aqueous (+)- or (−)-10-camphorsulfonic acid (HCSA) using polystyrene sulfonate (PSS) as a steric stabilizer and codopant. Potentiostatic polymerization at +0.9 V (vs Ag/AgCl) was employed. The colloidal PAn·HCSA/PS…
Bismuth sodium titanate, (Bi 1/2 Na 1/2 )TiO 3 (BNT)-based solid solution, a (Bi 1/2 Na 1/2 )TiO 3 – b KNbO 3 – c 1/2(Bi 2 O 3 ·Sc 2 O 3 ) ( a + b + c =1), [KTNS(100 a /100 b /100 c )], was studied for its dielectric, ferroelectric and piezoelectric properties, as a new group of lead-free piezoelectric ceramics. Elect…
We report neutron scattering experiments on several Al-Pd-Mn liquid alloys with Mn content between 3.5 and 7.2 at. % which are in thermodynamical equilibrium with icosahedral quasicrystalline or approximant phases. The results reveal an overall similarity between the structure factor in the solid and in the liquid sta…
We investigate the local structural heterogeneities that may appear in liquid water by studying a model of interacting water pentamers. We find local energy minima which we identify with well-defined configurations, and advance the hypothesis that one of these configurations may be related to local “high-density” stru…