A simple method to tune the optical properties of porous anodic alumina （PAA） films embedded with Co nanowires （PAA@Co nanocomposite films） is reported in this paper. The films exhibit vivid structural colors and ...A simple method to tune the optical properties of porous anodic alumina （PAA） films embedded with Co nanowires （PAA@Co nanocomposite films） is reported in this paper. The films exhibit vivid structural colors and magnetic properties. The optical properties of the films can be effectively tuned by adjusting the thickness of the PAA template. The deposition of Co nanowires greatly increases the color saturation of the PAA films. The theoretical results of the changes in structural color according to the Bragg-Snell formula are consistent with the experimental results. PAA@Co films can be used in many areas, including decoration, display, and multifunctional anti-counterfeiting applications.展开更多
Brown needle-like crystals of CaEr2S4 were isolated as the major product from a reaction of elements and binary sulfides by a two-step flux technique. CaEr2S4 crystallizes in the orthorhombic space group Pnma with a=1...Brown needle-like crystals of CaEr2S4 were isolated as the major product from a reaction of elements and binary sulfides by a two-step flux technique. CaEr2S4 crystallizes in the orthorhombic space group Pnma with a=12.845（4）, b=3.862（4）, c=13.001（2）（A）, V=645.0（7）（A）3,Z=4, F（000）=880,μ（MoKα）=27.794 mm^-1, the final R=0.0528 and wR=0.0562 for 1070observed reflections with I 〉 3σ（I）. The CaEr2S4 structure forms a three-dimensional framework that consists of interconnected tetra-octahedral Er4S18 fragments. Ca^2＋cations, in a monocapped trigonal prism geometry, are stuffed in two parallel rows into the one-dimensional channels along the b direction. CaEr2S4 is an infrared-transparent semiconductor with a band gap of 1.81 eV. Magnetic susceptibility measurements over 6～300 K indicate a Curie-Weiss paramagnetic behavior for the phase, with an effective magnetic moment of 9.64（1） μB per Er^3＋ ion.展开更多
The TiO2-Co-TiO2 sandwich films were successfully grown on glass and silicon substrata making alternate use of radio frequency reactive magnetron sputtering and direct current magnetron sputtering. The structures and ...The TiO2-Co-TiO2 sandwich films were successfully grown on glass and silicon substrata making alternate use of radio frequency reactive magnetron sputtering and direct current magnetron sputtering. The structures and properties of these films were identified with X-ray diffraction （XRD）, Raman spectra and X-ray photoemission spectra （XPS）. It is shown that the sandwich film consists of two anatase TiO2 films with an embedded Co nano-film. The fact that, when the Co nano-film thickens, varied red shifts appear in optical absorption spectra may well be explained by the quantum confinement and tunnel effects. As for magnetic properties, the saturation magnetization, remnant magnetic induction and coercivity vary with the thickness of the Co nano-films. Moreover, the Co nano-film has a critical thickness of about 8.6 mn, which makes the coercivity of the composite film reach the maximum of about 1413 Oe.展开更多
基金supported by the Natural Science Foundation of Hebei Province,China(Grant No.A2012205038)
文摘A simple method to tune the optical properties of porous anodic alumina （PAA） films embedded with Co nanowires （PAA@Co nanocomposite films） is reported in this paper. The films exhibit vivid structural colors and magnetic properties. The optical properties of the films can be effectively tuned by adjusting the thickness of the PAA template. The deposition of Co nanowires greatly increases the color saturation of the PAA films. The theoretical results of the changes in structural color according to the Bragg-Snell formula are consistent with the experimental results. PAA@Co films can be used in many areas, including decoration, display, and multifunctional anti-counterfeiting applications.
基金This work was partially supported by the NSF of Fujian Province (Z0513020, A042002)the NSF for Distinguished Young Scientist of China (20425104) and the NSF of CAS (KJCX2-SW-h05)
文摘Brown needle-like crystals of CaEr2S4 were isolated as the major product from a reaction of elements and binary sulfides by a two-step flux technique. CaEr2S4 crystallizes in the orthorhombic space group Pnma with a=12.845（4）, b=3.862（4）, c=13.001（2）（A）, V=645.0（7）（A）3,Z=4, F（000）=880,μ（MoKα）=27.794 mm^-1, the final R=0.0528 and wR=0.0562 for 1070observed reflections with I 〉 3σ（I）. The CaEr2S4 structure forms a three-dimensional framework that consists of interconnected tetra-octahedral Er4S18 fragments. Ca^2＋cations, in a monocapped trigonal prism geometry, are stuffed in two parallel rows into the one-dimensional channels along the b direction. CaEr2S4 is an infrared-transparent semiconductor with a band gap of 1.81 eV. Magnetic susceptibility measurements over 6～300 K indicate a Curie-Weiss paramagnetic behavior for the phase, with an effective magnetic moment of 9.64（1） μB per Er^3＋ ion.
基金Aeronautical Science Foundation of China (03G51069)Items of Engineering Research Institute, Peking University (ERIPKU-204031)
文摘The TiO2-Co-TiO2 sandwich films were successfully grown on glass and silicon substrata making alternate use of radio frequency reactive magnetron sputtering and direct current magnetron sputtering. The structures and properties of these films were identified with X-ray diffraction （XRD）, Raman spectra and X-ray photoemission spectra （XPS）. It is shown that the sandwich film consists of two anatase TiO2 films with an embedded Co nano-film. The fact that, when the Co nano-film thickens, varied red shifts appear in optical absorption spectra may well be explained by the quantum confinement and tunnel effects. As for magnetic properties, the saturation magnetization, remnant magnetic induction and coercivity vary with the thickness of the Co nano-films. Moreover, the Co nano-film has a critical thickness of about 8.6 mn, which makes the coercivity of the composite film reach the maximum of about 1413 Oe.
