Effect of CsxWO 3 Nanoparticles Content and Atomic Ratio for Near Infrared Cut-off Characteristics
In this work, the ceramic nanocomposites films with homogeneous dispersions of tungsten bronze nanoparticles with ternary additive cesium have been prepared by mixing Urethane acrylic/UVcoating binder and dispersed sol depending on the atomic ratio and the particle contents. Furthermore, we are synthesized the CsxWO3 with different annealing at 700, 800, and 900 °C in an N2 gas for 1 hr respectively. The structure and sizes of ceramic particles was observed XRD and PSA spectrometer, the heat-shielding properties of their films were investigated by NIR spectrometer. Synthesized Cs0.33WO3 particles with annealing at 800 °C typically formed hexagonal tungsten bronze structure for good absorption of NIR, size observed as being 30-100 nm and <150 nm. Especially, remarkable absorption of NIR wavelength ranges makes ceramic composite films good candidate for use as a heat shielding window, it clearly shows useful for applications where heat shield is required.
Facile synthesis and structure characterization of hexagonal tungsten bronzes crystals
Abstract A facile molten-salt route was used to synthesize hexagonal Cs 0.33 WO 3 , Rb 0.33 WO 3 and K 0.30 WO 3 crystals. The three isostructural compounds were successfully prepared from the reaction of M x WO 3 powders (M = Cs, Rb, K) in the CsCl/NaCl, RbCl/NaCl and KCl/NaCl fluxes, respectively. The structure determination and refinement, based on single-crystal X-ray diffraction data, are in agreement with previous works, possessing space group P6 3 /mcm. The a and c parameters vary non-linearly with increasing radii of the M + cations (r M ) that is coordinated to twelve oxygen atoms. Both the volumes of unit-cell and WO 6 octahedra vary linearly with r M , which become smaller from Cs 0.33 WO 3 to K 0.30 WO 3 . The distortion of WO 6 octahedra as well as isotropic displacement parameters increases from Cs 0.33 WO 3 to K 0.30 WO 3 . The geometry of the WO 6 octahedron becomes more regular with increasing r M . These structural trends arise from the effective size of the M + cation.
Photoinduced spin-state transition of Co3+ in the layered perovskite manganite thin film
The photoinduced effect, at different temperatures, on layered perovskite manganite La1.2Sr1.8Mn1.8Co0.2O7 thin film deposited on a SrTiO3(100) substrate has been studied using a He–Ne laser (632.8 nm) with the power of output 25 mW at low temperatures. The electrical transport and magnetic properties of the film are investigated systematically in the temperature region from 20 to 300 K. The resistance shows a significant decrease at low temperatures (T<90 K) under laser irradiation, which can be interpreted in terms of the spin-state transition of Co3+ ions. The magnetic field combined with the laser is also used to detect the photoinduced effect of the spin-glass state. The time dependence of the metastable system under several applied fields was also discussed. The system has the ability to keep a persistent memory of the magnetic history imprinted in its zero-field resistance.