The Influence of Yb3+ Co-Doping on Optical Properties of Sm3+-Doped Sodium Tellurite Glasses

2014 ◽  
Vol 895 ◽  
pp. 359-362
Author(s):  
Fakhra Nawaz ◽  
Muhammad Rahim Sahar ◽  
Sib Krishna Ghoshal
Keyword(s):  
Optical Properties ◽  
Nir Spectroscopy ◽  
Band Gap Energy ◽  
Oscillator Strengths ◽  
Tellurite Glasses ◽  
X Rays ◽  
Broad Absorption Band ◽  
Co Doping ◽  
Sodium Tellurite

A series of Sm3+-doped sodium tellurite glasses co-doped with Yb3+were synthesized by melt quenching technique. The amorphous nature of the glasses was confirmed by X-Rays diffraction technique. From UV-Vis-NIR spectroscopy, eight absorption peaks of Sm3+ions are observed. The broad absorption band in the range of ~870-1100 nm corresponds to the superposition of Sm3+:6H5/26F11/2and Yb3+:2F7/22F5/2transitions. The experimental and theoretical oscillator strengths of these bands were calculated by Judd-Ofelt theory. The optical band gap energy (Eopt) values for direct allowed transition and Urbach energy were found to be in the range of 2.73-2.91 eV and 0.21-0.27 eV respectively. Four luminescence emission bands4G5/26H5/2,6H7/2,6H9/2and6H11/2were revealed under 406 nm excitation and intensity of all bands is found to be quenched with addition of Yb3+ions. The role of Yb3+co-doping in the optical properties is compared and understood.

Direct thermal oxidization evaporation growth, structure, and optical properties of single-crystalline nanobelts of molybdenum trioxide

2007 ◽  
Vol 22 (6) ◽  
pp. 1609-1617 ◽  
Author(s):  
W.G. Chu ◽  
L.N. Zhang ◽  
H.F. Wang ◽  
Z.H. Han ◽  
D. Han ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Optical Properties ◽  
Molybdenum Trioxide ◽  
Band Gap Energy ◽  
Diffraction Field ◽  
Large Strains ◽  
Layer By Layer ◽  
X Rays ◽  
Dislocation Configuration ◽  
Single Crystalline

Single-crystalline nanobelts of molybdenum trioxides were grown by direct thermal oxidization evaporation of metal molybdenum foils. Their structures, defects, and optical properties were investigated via x-ray diffraction, field-emission scanning electron microscopy, high-resolution transmission electron microscopy (HRTEM), atomic force microscopy, micro-Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and ultraviolet-visible spectroscopy (UV-VIS). Single-crystalline nanobelts were identified as an orthorhombic structure with an average stoichiometry of MoO3.02analyzed by energy dispersive spectroscopy of x-rays. The length, width, and thickness of a nanobelt were determined to be parallel to the b, c, and aaxis of the MoO3unit cell, respectively. The thickness of the nanobelt increased by integer multiples of 0.5ain a layer-by-layer fashion during growth. A density of dislocations as high as about 1.2 × 1013cm−2was formed, which may be attributed to relaxation of large strains during cooling. A special dislocation configuration was observed by HRTEM, which was well reproduced by image simulations based on the proposed model. The resulting morphology of nanobelts was proposed to be governed by growth kinetics. Micro-Raman and FTIR spectra were successfully analyzed on the basis of vibration of MoO6octahedra. It was found that micro-Raman spectra were quite dependent on the size of the nanobelts. A band gap energy of 3.04 eV derived from UV-VIS measurements was observed to be red shifted relative to the previously reported experimental values, which may be due to the presence of a high density of defects.

scholarly journals Thermal stability and Judd-Ofelt analysis of optical properties of Sm3+-doped sodium tellurite glasses

2017 ◽  
Author(s):  
Saman Q. Mawlud ◽  
Mudhafar M. Ameena ◽  
Md. Rahim Sahar ◽  
Zahra A. Said Mahraz ◽  
Kasim Fawzy Ahmed
Keyword(s):  
Thermal Stability ◽  
Optical Properties ◽  
Tellurite Glasses ◽  
Sodium Tellurite

Optical Properties of Erbium Doped Tellurite Glasses

2016 ◽  
Vol 864 ◽  
pp. 37-41 ◽  
Author(s):  
Mukhayyarotin Niswati Rodliyatul Jauhariyah ◽  
Cari ◽  
Ahmad Marzuki
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Room Temperature ◽  
Optical Band Gap ◽  
Band Gap Energy ◽  
Tellurite Glasses ◽  
Ion Content ◽  
Gap Energy ◽  
Erbium Doped ◽  
Angle Method

This paper presents the optical properties of erbium doped tellurite glasses with the composition of 55TeO2-2Bi2O3-35ZnO-5PbO-(3-x)Na2O-xEr2O3 where x = 0, 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mol% . Refractive index of the glasses was measured using Brewster’s angle method and their optical absorption spectra were measured in spectral range 200 – 1100 nm recorded at room temperature. The results show that the glass refractive index increases with the increase of Er3+ ion content in the glass and the optical band gap energy decreases with the increase of erbium content in the glass.

Probing the role of (Nd, Ni) co-doping on structural and optical properties of nanocrystalline BiFeO3

2019 ◽  
Author(s):  
Mehroosh Fatema ◽  
Anand Somvanshi ◽  
Samiya Manzoor ◽  
Shahid Husain
Keyword(s):  
Optical Properties ◽  
Structural And Optical Properties ◽  
Co Doping

Optical Absorption of Nd3+ Doped Tellurite Glass Containing Ag Nanoparticles

2014 ◽  
Vol 895 ◽  
pp. 236-240
Author(s):  
N.A. Azmi ◽  
Md Rahim Sahar ◽  
Sib Krishna Ghoshal
Keyword(s):  
Optical Properties ◽  
Metallic Nanoparticles ◽  
Light Emission ◽  
Nir Spectroscopy ◽  
Tellurite Glasses ◽  
Direct Transition ◽  
Ag Nps ◽  
Absorption Bands ◽  
Optical Behavior ◽  
Rare Earth Doped

Understanding the optical properties of rare earth doped tellurite glasses with embedded metallic nanoparticles (NPs) are promising for photonics. Series of Nd3+ doped tellurite glasses containing Ag NPs having chemical composition (70-x)Te2O3-10MgO-20Li2CO3-0.5Nd2O3-xAg, where 0.0 x 1.0 mol% are synthesized. Their optical properties are measured using UV-Vis-NIR spectroscopy. The absorption spectra exhibits nine absorption bands in the wavelength range of 300-900 nm are obtained and the glass showed light emission due to 4F3/2 4I9/2 transition. The values of optical band gap Eopt and Urbach energy Eu are evaluated from the absorption band. The value of Eopt is found to lie between 2.78 and 2.91 eV for the direct transition whereas the Eu values lie between 0.27 and 0.37 eV. The optical behavior of the samples is studied with varying Ag NPs content and the results are compared with similar studies.

Role of lithium ions on the physical, structural and optical properties of zinc boro tellurite glasses

2018 ◽  
Vol 92 (7) ◽  
pp. 901-909 ◽  
Author(s):  
S. Rani ◽  
N. Ahlawat ◽  
R. Parmar ◽  
S. Dhankhar ◽  
R. S. Kundu
Keyword(s):  
Optical Properties ◽  
Tellurite Glasses ◽  
Structural And Optical Properties ◽  
Lithium Ions

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

1988 ◽  
Vol 46 ◽  
pp. 530-531
Author(s):  
L. T. Germinario
Keyword(s):  
Background Radiation ◽  
Metal Cluster ◽  
Single Element ◽  
Beam Diameter ◽  
X Rays ◽  
X Ray ◽  
Major Interest ◽  
Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

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