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optical spectroscopy and crystal-field strength of Cr^(3+) in various solid matrixes

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Rare Metals 2006年第1期25卷 51-57页

作者： XIA Haiping WANG Jinhao WANG Hongyin ZHANG Jianli ZHANG Yuepin XU Tiefeng The Laboratory of Photo-electronic Materials Ningbo University Ningbo 315211 China

The Cr^3＋：BeAl2O4 crystal, Cr^3＋：LiNbO3 crystal, and ZnO-Al2O3-SiO2 glass-ceramic were obtained by the Czochralski technique, Bridgman method, and melting processing, respectively. The optical absorption and emission spectra of the above Cr^3＋-incorporated solid-state materials were recorded. The technical parameters for growing high-quality Cr^3＋：BeAl2O4 and Cr^3＋：LINbO3 crystals were obtained. The results indicate that the optical absorption and fluorescence spectra of Cr^3＋ show quite a few differences in various matrixes. The sharp line emissions were observed in the Cr^3＋：BeAl2O4 and Cr^3＋：LiNbO3 crystals. The crystal-field parameters （Dq） for Cr^3＋. in different matrixes were calculated from their corresponding spectra. It is indicated that Cr^3＋：BeAl2O4 and Cr^3＋：LiNbO3 belong to the high-field site crystal, while the Cr^3＋ ZnO-Al2O3-SiO2 glass and glass-ceramic belong to the weak-field site crystal.

关键词： special functional inorganic materials optical spectroscopy optical measurement Cr^3+ ion matrix

optical spectroscopy of Er^(3+) and Er^(3+)/Yb^(3+)Co-doped Bi_2O_3-GeO_2-B_2O_3-ZnO Glasses

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Journal of Rare Earths 2006年第4期24卷 408-412页

作者：夏海平章践立王金浩张约品 Laboratory of Photo-Electronic Materials Ningbo UniversityNingbo 315211 China

The （60 - x）Bi2O3 - xGeO2-30B2O3-10ZnO （x = 5, 10, 20, 30 molar percent） glasses doped with Er^3＋ and Er^3＋/Yb^3＋ were fabricated using the melting method. The thermal stability of the glasses was studied with their DTA curves. The results show that the difference between the glass transition temperature and the crystallization onset temperature increases with the increase of GeO2 content, indicating that the thermal stability of the glass has become better. The absorption spectra were recorded and the stimulated emission cross sections were calculated using the McCumber theory. The Ω2, O4, and Ω6 parameters,the transition probability, the radiative lifetime, and the fluorescence branch ratio of Er^3＋ for optical transition were calculated from their absorption spectra in terms of reduced matrix U^（t）（λ = 2, 4, 6） character for optical transitions. The infrared emission of Er^3＋ was measured upon excitation with 970 nm light and the full width at half-maximum （FWHM） was estimated from the emission spectra. The pumping efficiency and the intensity of the emission at the 1.54 μm band of Er^3＋ were enhanced considerably by co-doping Yb^3＋ .

关键词： Bi-based glass GeO2 Er^3+ Er^3+/Yb^3+ thermal stability optical spectroscopy rare earths

optical spectroscopy of Pr3+ Ion Singly Doped LiLuF4 Single Crystal by Bridgman Method

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Chinese Journal of Chemical Physics 2019年第6期32卷 661-666,I0002页

作者： Li-zhi Fang Xiong Zhou Hai-ping Xia Jian-xu Hu Jian-li Zhang Bao-jiu Chen Key laboratory of Photo-electronic Materials Ningbo UniversityNingbo 315211China Department of Physics Dalian Maritime UniversityDalian 116026China

High quality LiLuF4 single crystals doped with various Pr3+ ions were synthesized by a vertical Bridgman method in completely sealed platinum crucibles. The excitation spectra spans from 420 nm to 500 nm. The prepared single crystals exhibit a blue band at 480 nm(3P0→3H4), a green band at 522 nm (3P1→3H5), and a red band at 605 nm (1D2→3H4)when excited at 446 nm;their corresponding average lifetimes are 38.5μs, 37.3μs, and 36.8μs, respectively, which are much longer than those in oxide single crystals. The effects of excitation wavelength and doping concentration on emission intensities and chromaticity coordinates are investigated. The optimal Pr3+ concentration is confirmed to be 0.5%.The temperature dependent emission shows that the emission intensity constantly decreases with the increase of temperature from 298 K to 443 K due to the enhancement of nonradiative quenching at high temperature. The 3P0→3H4 transition is the most vulnerable to temperature, followed by the 3P1→3H5 transition and 1D2→3H4 transition.

关键词： Pr3+ ion LiLuF4 single crystal optical spectroscopy

The clinical effectiveness of reflectance optical spectroscopy for the in vivo diagnosis of oral lesions

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International Journal of Oral Science 2014年第3期6卷 162-167页

作者： Diana V Messadi Fariba S Younai Hong-Hu Liu Gao Guo Cun-Yu Wang Section of Oral Medicine and Orofacial Pain Division of Oral Biology and Medicine School of Dentistry University of California at Los Angeles Section of Oral Biology Division of Oral Biology and Medicine School of Dentistry University of California at Los Angeles Division of Public Health and Community Dentistry School of Dentistry University of California at Los Angeles David Geffen School of Medicine and Fielding School of Public Health

optical spectroscopy devices are being developed and tested for the screening and diagnosis of oral precancer and cancer lesions. This study reports a device that uses white light for detection of suspicious lesions and green–amber light at 545 nm that detect tissue vascularity on patients with several suspicious oral lesions. The clinical grading of vascularity was compared to the histological grading of the biopsied lesions using specific biomarkers. Such a device, in the hands of dentists and other health professionals, could greatly increase the number of oral cancerous lesions detected in early phase. The purpose of this study is to correlate the clinical grading of tissue vascularity in several oral suspicious lesions using the IdentafiH system with the histological grading of the biopsied lesions using specific vascular markers. Twenty-one patients with various oral lesions were enrolled in the study. The lesions were visualized using IdentafiH device with white light illumination, followed by visualization of tissue autofluorescence and tissue reflectance. Tissue biopsied was obtained from the all lesions and both histopathological and immunohistochemical studies using a vascular endothelial biomarker（CD34） were performed on these tissue samples. The clinical vascular grading using the green–amber light at 545 nm and the expression pattern and intensity of staining for CD34 in the different biopsies varied depending on lesions, grading ranged from 1 to3. The increase in vascularity was observed in abnormal tissues when compared to normal mucosa, but this increase was not limited to carcinoma only as hyperkeratosis and other oral diseases, such as lichen planus, also showed increase in vascularity. optical spectroscopy is a promising technology for the detection of oral mucosal abnormalities; however, further investigations with a larger population group is required to evaluate the usefulness of these devices in differentiating benign lesions from potentially

关键词： ansiosenesis optical spectroscopy oral lesions

optical spectroscopy of Er^(3+), Er^(3+)/Yb^(3+) Co-doped Bi_2O_3-GeO_2-B_2O_3-ZnO Glasses

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Journal of Rare Earths 2005年第5期23卷 550-550页

作者： Xia Haiping Zhang Jianli Wang Jinhao Zhang Yuepin Laboratory of Photo-Electronic Materials Ningbo University Ningbo 315211 China

The （60 - x） Bi2O3-xGeO2-30B2O3-10ZnO （x = 5, 10, 20, 30 molar percent） glasses doped with Er^3＋ and Er^3＋/Yb^3＋ were fabricated by melting method. The thermal stability of the glasses was studied by their DTA curves. The results indicate that the difference between the glass transition temperature and the crystallization onset temperature increase as increase of GeO2 content, indicating that the thermal stability of the glass becomes better. The absorption spectra were recorded. The stimulated emission cross sections were calculated by McCumber theory. The Ω2, Ω4, and Ω6 parameters, transition probability, radiative lifetime, fluorescence branch ratio of Er^3＋ for optical transition were calculated from their absorption spectra in terms of reduced matrix U^（1）（λ = 2, 4, 6） character for optical transitions. The infrared emission was measured by excitation with 970 nm light and the FWHM was estimated from their emission spectra. The pumping efficiency and the intensity of emission at the band of 1.54 μm are enhanced greatly by addition of Y2O3.

关键词： Bi-based glass GeO2 Er^3 + Er^3 +/Yb^3+ thermal stability optical spectroscopy rare earths

Identification of Natural,Synthetic and Treated Diamonds Using optical spectroscopy

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Identification of Natural,Synthetic and Treated Diamonds Usi...

In-situ high-pressure behaviors of double-perovskite Sr_2ZnTeO_6

2011中国珠宝首饰学术交流会

作者： Alan T Collins Physics Department King’s College London

This review describes how optical spectroscopy may be employed to identify natural diamonds and diamonds grown by high-pressure,high-temperature(HPHT) synthesis or chemical vapour *** absorption and luminescence spectroscopy it is also possible to determine,in the majority of cases,whether the colour of a diamond is natural or has been changed by some form of treatment- either HPHT processing,radiation damage and annealing,or a combination of both methods.

关键词： optical spectroscopy natural diamond synthetic diamond treated-colour diamonds

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Chinese Physics B 2013年第5期22卷 644-649页

作者：韩丹丹高伟李娜娜唐瑞莲李会马艳梅崔启良朱品文王欣 State Key Laboratory of Superhard Materials Jilin University

Structural and spectroscopic properties of Sr2ZnTeO6 （SZTO） were investigated by angle-dispersive synchrotron X- ray powder diffraction and Raman spectroscopy in a diamond anvil cell up to 31 GPa at room temperature. Although SZTO remained stable up to the highest pressure, the different pressure coefficients of the normalized axial compressibility were obtained as βab=8.16×10-3 GPa-1 andβc=7.61 x 10-3 GPa-1. The bulk modulus B0 was determined to be 190（1） GPa by fitting the pressure-volume data using the Birch-Mumaghan equation of state. All the observed Raman modes exhibited a broadening effect under high pressure. The vibrational band V1 around 765 cm-1, which is associated with the Te-O stretching mode in the basal plane of the TeO6 octahedron had the largest pressure coefficient, and the Griineisen parameters for all the observed phonon modes were also calculated and presented. These parameters could be used to measure the amount of uniaxial or biaxial strain, providing a fundamental tool for monitoring the magnitude of the shift of phonon frequencies with strains.

关键词： crystal structure high pressure X-ray diffraction optical spectroscopy

Pressure-induced color change arising from transformation between intra-and inter-band transitions in LuH_(2±x)N_(y)

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 161-166页

作者： Zhe Liu Yingjie Zhang Shenyang Huang Xue Ming Qing Li Chenghao Pan Yaomin Dai Xiaoxiang Zhou Xiyu Zhu Hugen Yan Hai-Hu Wen Center for Superconducting Physics and Materials National Laboratory of Solid State Microstructures and Department of PhysicsNational Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China State Key Laboratory of Surface Physics Key Laboratory of Micro and Nano-Photonic Structures of the Ministry of EducationDepartment of PhysicsFudan UniversityShanghai 200433China

The pressure-induced color change in the nitrogen-doped lutetium hydride has triggered extensive discussions about the underlying physics and potential ***,we study the optical response of LuH_(2±x)N_(y)in a broad frequency range at ambient pressure and its evolution with pressure in the visible spectral *** broad-band optical spectra at ambient pressure reveal a Drude component associated with intra-band electronic transitions and two Lorentz components(L1 and L2)arising from inter-band electronic *** application of pressure causes a spectral weight transfer from L1 to the Drude component,leading to a blue shift of the plasma edge in the reflectivity spectrum alongside a reduction of the high-frequency *** results suggest that the pressure-induced color change in LuH_(2±x)N_(y)is closely related to the transformation between intra-and inter-band electronic transitions,providing new insights into the mechanism of the pressure-induced color change in LuH_(2±x)N_(y).

关键词： nitrogen-doped lutetium hydride optical spectroscopy high-pressure technique color change

One-dimensional Supramolecular Chain Based on a Dinuclear Terbium(Ⅲ) 4-Cyanobenzoate Complex

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Chinese Journal of Structural Chemistry 2007年第7期26卷 805-810页

作者：李国清李艳邹文强陈其湧吴阿清郑发鲲郭国聪 Chemistry and Life Science School Quanzhou Normal University Quanzhou State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter The Chinese Academy of Sciences

A new dinuclear Tb（Ⅲ） 4-cyanobenzoate complex [Tb2（4-cba）6（phen）2] （4-Hcba = 4-cyanobenzoic acid and phen = 1,10-phenanthroline） 1 has been synthesized by solvothermal reaction in an ethanol/water mixed solution at 100℃ and structurally characterized by single-crystal X-ray diffraction. Crystallographic data： C72H40N10O12Tb2, Mr=1554.98, triclinic Pi, a = 9.903（3）, b = 11.769（8）, c = 15.078（8）A, a = 111.42（12）, It = 96.37（19）, γ = 101-24（14）°, V= 1572（1）A3, Z= 1, Dc = 1.642 g/cm^3, F（000） = 768 μ = 2.305 mm^-1, the final R = 0.0205 and wR = 0.0543 for 5479 reflections with I 〉 2σ（I）. Structural analysis shows that 1 displays an isolated dinuclear structure. Two eight-coordinated Tb（Ⅲ） ions are bridged by four 4-cba ligands in the syn-syn bidentate coordination mode, and two other 4-cba ligands chelate these two Tb（Ⅲ） ions. The title complex molecules are connected through π-π stacking interactions to generate a one-dimensional supramolecular chain, The characteristic infrared spectra, luminescent properties and thermogravimetric analyses have also been discussed.

关键词： terbium(Ⅲ) complex 4-cyanobenzoic add crystal structure π-π stacking optical spectroscopy