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Abstract: ZnO thin films were grown on (111) CaF2 substrates by magnetron sputtering at room temperature. Structural and optical properties of the ZnO thin films were studied. XRD analysis showed that the ZnO thin films had the (002) preferential orientation. The transmittance of ZnO thin films was over 80% in the visible range. The optical band gap of the ZnO thin films was 3.26 eV. The optical constants of the ZnO thin films in the wavelength range 300–1000 nm were obtained by infrared spectroscopic ellipsometry measurement. PL spectra of ZnO thin films showed strong UV near-band-edge emission peak at 376.5 nm and weak visible red emission at 643.49 nm using He–Cd laser as the light source, using a synchrotron radiation light source PL spectra showed three emission peak at 320 nm, 410 nm and 542 nm respectively. [Copyright &y& Elsevier]

Abstract: Ce-coped Lu2SiO5 powders were prepared by the solid-state reaction method. The effects of flux and atmosphere on the powders structure and properties were investigated by X-ray diffraction (XRD) and spectral measurement. The XRD results show that the samples calcined at 1300°C without using flux were mainly Lu2O3, SiO2 and a small amount of Lu2SiO5, while the samples with Li2SO4 flux are mainly Lu2SiO5. Furthermore, atmosphere is little effective on powder structure. Absorption band of Lu2SiO5 powders shows five peaks at 215nm, 241nm, 275nm, 318nm and 382nm, the absorption intensity of samples prepared in air is higher than that of samples prepared in reduced atmosphere. Broad emission band and stronger emission intensities have been found in Lu2SiO5 powders prepared in reduced atmosphere. The excitation spectra of Lu2SiO5 powders prepared in reduced atmosphere are composed of four bands at 240nm, 271nm, 302nm and 360.6nm. It can be concluded that flux and atmosphere during preparation is favorable for LSO powders emission and is an effective method to decrease calcining temperature. [Copyright &y& Elsevier]

Luminescent transparent ceramics (Tb 1-x Y x) 3 Al 5 O 12 (x = 0, 0.2, 0.5, 0.8) are successfully prepared by a solid-state method with additional hot isostatic pressing (HIP) treatment, and the structure and properties are investigated by XRD, SEM, PL, UV–Vis spectrophotometry and ellipsometry. The Y-containing samples are shown to be solid solution phases between TAG and YAG. The PL intensity is 14 times stronger with the incorporation of 80 mol.% Y, and the 5D 4 →7F 5 emission lifetime of Tb3+ is prolonged from 0.357 to 3.035 ms at room temperature. A unique magnetoluminescence emerges upon the incorporation of Y, showing an interesting emission decrease to 55% as the Y content reaches 80 mol.%. Remarkably, this magnetoluminesence can occur at room temperature without an intense magnetic field. Based on our work, transparent (Tb 1-x Y x) 3 Al 5 O 12 ceramics exhibit the potential for applications in green emitters, optical instruments and photoelectric devices. In particular, the magnetoluminescence provides a simple, noncontact and nondestructive route for probing magnetic fields. [ABSTRACT FROM AUTHOR]

(Tb x Y 1−x ) 3 Al 5 O 12 (x = 0.2, 0.5, 0.8) transparent ceramics were synthesized by a solid-state reaction and HIP. All the samples were pre-sintered at 1650 °C for 4 h in a muffle and later HIPed at 1650 °C for 3 h. (Tb 0.2 Y 0.8 ) 3 Al 5 O 12 transparent ceramics exhibit best microstructure with an average grain size of approximately 5.22 μm and optical transmittance of over 65% in the region of 500–1600 nm. Additionally, average grain sizes of all the samples are less than 10 μm. XRD scanning patterns indicate that only the (Tb 0.8 Y 0.2 ) 3 Al 5 O 12 samples have little secondary phases. [ABSTRACT FROM AUTHOR]

Te doped Yttrium-aluminum (Y 2 O 3 –Al 2 O 3) system powders were synthesized by solid-state method. The structure and optical properties were investigated by XRD, SEM, XPS and PL. XRD analysis indicated that the samples transform from YAM, YAP to YAG phase as the sintering temperature rises. The samples sintered below 1200 °C have a broad emission centered at 604 nm with a lifetime up to 13.33 μs under room temperature. While in the mix phase of YAP and YAG, a sharp and intense emission peak centered at 715 nm was monitored with a lifetime up to approximate 2.76 ms. Moreover, the band structure and density of states for Te doped YAGwere investigated by first-principle calculations. [ABSTRACT FROM AUTHOR]