Advanced Materials Research Vols. 399-401

Abstract: POT (poly (o-toluidine)) was synthesized on ITO/glass by using electrochemical method and the effect of different reaction conditions such as scan rate, the concentrations of monomer and sulfuric acid, and cycle times on the POT was studied. The resulting POT was characterized by spectroscopy such as FT-IR, Roman, and UV-vis methods. The surface morphology of protruding island shape was recorded by scanning electronic microscope (SEM). The electrochromic properties were found that the color of the polymer can turn from green to blue reversibly by increasing the applied voltage. The anode of the solar cell was made of FTO/glass covered with nano-TiO₂/POT showed good photo-electron conversion performance which indicated the potential application in electrochromic and solar cell devices.

Abstract: Abstract. Rapidly quenched ribbons of Fe_63.5Co₁₀Si_13.5B₉Cu₁Nb₃ alloy were annealed at 550°C in a vacuum for 1h and milled to powders. Cold-pressed nanocrystalline powder cores were fabricated using 1-5wt.% of epoxy E-44 as the binder and 1wt.% of Zn-stearate for lubrication under the pressure 155-200KN. The microstructure and morphology of powders were characterized with XRD and SEM. The effective permeability (μe) and quality factor (Q) were tested by using LCR HiTESTER 3532-50 in the range of 1–5000 kHz. The results show that the μe of the powder cores increased with the particle size. Powder cores with 2wt.% binder exhibited higher μe, but lower Q compared with samples with 3wt.% binder. Increase of the forming pressure helps improve μe, but the excessive stress caused by the forming pressure had a negative effect for μe.

Abstract: The effect of C substitution on the glass forming ability (GFA) and soft magnetic properties of Fe-based bulk metallic glasses (BMG) Fe_79.4-xC_xSi_3.5B_5.1P_8.9Mo₃Mn_0.1 (x = 4.2, 5.2, and 7.0) alloys have been investigated. It is revealed that fully glassy alloy rods with diameters up to 4 mm can be prepared by conventional copper mold casting method even using the low-cost industrial Fe-P master alloy. Properly substituting of Fe by C gives rise to an enhancement of GFA. Moreover, all the samples exhibit good soft magnetic properties with high saturation magnetization up to 1.16 T and low coercivity of 204 A/m.

Abstract: In this paper, Ba₃MgSi₂O₈: Eu²⁺, Mn²⁺ phosphor was synthesized by the sol-gel method and high temperature solid-state reaction method. The structure and emission spectrum excited by near violet light were investigated. we studied the process of phase change in roasting and determined the approximate crystallization temperature of Ba₃MgSi₂O₈: Eu²⁺, Mn²⁺ phosphors. Our results demonstrate that 514 nm emission bands were from Eu²⁺ ions replacing of the sites of Ba²⁺ in Ba₂SiO₄. 440 nm emission bands originated from Eu2+ ions substituting the sites of Ba²⁺ in Ba₃MgSi₂O₈, corresponded to 4f⁶5d¹→4f⁷ transition of Eu2+ ions. 615 nm emission bands ascribed to Mn2+ ions taking place of the sites of Mg²⁺ ions, corresponded to 4T→6A red launch of Mn²⁺ ions.

Abstract: Monoclinic La₂(WO₄)₃ nanophosphors codoped with Tm³⁺ and Yb³⁺ ions were synthesized via hydrothermal process followed by heat treatment. Powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize as-prepared samples. The dependences of Yb³⁺/ concentration and laser pumping power on the upconversion emissions were extensively investigated. The results show that upconversion luminescence increases with the Yb³⁺/ concentration and gets its peak at 30 %. The upconversion mechanism and process in the Yb³⁺/Tm³⁺ codoped La₂(WO₄)₃ phosphors were analysed.

Abstract: A novel bi-Schiff-base Zn (II) complex, 1-acetyl-2-naphthol-4, 4’-diaminodiphenylmethane Zn (II), has been synthesized. The luminescent characterizations of the Zn (II) complex material have been studied in solid state and in organic solvents, and the effect of Mg (II) ion on the fluorescence of Zn (II) complex has also been investigated in organic solvents. The results show that the Zn (II) complex material emits weak green fluorescence at 536 nm in solid, emits strong blue fluorescence 451 nm in DMSO. However, there do have luminescent emissions in methanol and in ethanol duo to the influence of overtones.

Abstract: As additive, economic and low resistivity material was useful in the fields of electrostatic prevention and electromagnetism screening. Antimony-doped tin oxide(Sb:SnO₂)/talc composite was prepared for this purpose via a modified chemical deposition method using economic and natural talc as matrix. Effects of hydrolysis temperature, pH value, doping concentration of antimony, proportion of Sb:SnO₂ to talc, calcination temperature and time on the resistivity of the composite powder were investigated. The construction of Sb:SnO2/talc conductive composite was characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The resistivity of Sb:SnO₂/talc composite prepared at the optimum conditions decreased to 3.0×10³ Ω•cm, at the same time its whiteness was greatly improved.

Abstract: The junction temperature of GaN-based high-power green light emitting diodes is measured using the temperature coefficients of the diode forward voltage, from changes in temperature and changes in drive current to measure the LED junction temperature and the corresponding spectral, Respectively. Experiments show that, junction temperature due to environmental temperature increased, and the red shift of the spectral peak wavelength. When low temperature or less then the rated current range, the drive current increased in junction temperature rise due to the spectral peak wavelength blue shift . When the current is increased in the range of close to or greater than the rated current, leading to the junction temperature rise will cause spectral red shift . The peak wavelengths’ shift degree of 0.0579nm / k, 0.0751 nm / k and-0.1974nm / k, -0.0915 nm / k are calculated in both cases. The phenomenon is due to the LED junction temperature increases lead to band gap shrinkage, and the result of the role of spontaneous polarization and piezoelectric polarization in Ⅲ-nitride semiconductor materials.

Abstract: A novel photochromic hybrid diarylethene based on both isoxazole and cyano moieties was synthesized and its photochromic and fluorescent properties were also investigated. This compound exhibited good photochromism and functioned as a fluorescence switch upon alternating irradiation with UV and visible light both in solution and in PMMA film. Using this diarylethene 1c as optical storage was performed successfully.

Abstract: A novel poly(Schiff base) containing 4,7-disubstituted-1,10-phenanthroline (BAPcBDA) was synthesized by the polycondensation of 4,7-Bis(4-aminophenoxy)-l, l0-phenanthroline (BAP) with 4,4'-Biphenyldicarboxaldehyde (BDA). The polymeric complex was first prepared by the reaction of polymer (BAPcBDA) with NiSO₄. The structures of the monomer and polymer were characterized by IR, ¹H-NMR, and elemental analysis. The magnetic behaviors of the complex were measured as a function of magnetic field strength (0-50 kOe) at 5 K and as a function of temperature (5-300 K) at a magnetic field strength of 30 KOe. The results show that BAPcBDA-Ni²⁺ exhibited the features of an antiferromagnet.