The Experts below are selected from a list of 582 Experts worldwide ranked by ideXlab platform
Petr Mošner - One of the best experts on this subject based on the ideXlab platform.
-
Insertion of MoO3 in Borophosphate Glasses Investigated by Magnetic Resonance Spectroscopies
The Journal of Physical Chemistry C, 2016Co-Authors: Grégory Tricot, K. Ben Tayeb, Ladislav Koudelka, Petr Mošner, Hervé VezinAbstract:Insertion of MoO3 oxide in the mixed Borophosphate Glass network has been analyzed for the first time by advanced magnetic resonance spectroscopies. For the first time, the xMoO3-(100-x)(50PbO-10B2O3-40P2O5) composition line has been investigated by 1D (11B, 31P, 95Mo) and 2D-correlation NMR (11B DQ-SQ, 11B(31P) D-HMQC) at high magnetic field (18.8 T). The set of data allowed for analyzing both local and medium range orders and identifying the modifications in the BOB and/or BOP mixing induced by the MoO3 insertion. In a second step, continuous wave EPR has been used to detect the presence of Mo5+ ions, resulting from partial reduction of Mo6+ during the melting stage, and the chemical environment around the Mo5+ species has been documented for the first time by pulsed EPR technique (HYSCORE). Altogether, the data contribute to a better understanding of the Glass network modifications induced by the MoO3 insertion, including the nonlinear evolution of the Glass transition temperature that has been explain...
-
Insertion of MoO3 in Borophosphate Glasses investigated by magnetic resonance spectroscopies
Journal of Physical Chemistry C, 2016Co-Authors: Grégory Tricot, Ladislav Koudelka, Petr Mošner, K. Ben Tayeb, Hervé VezinAbstract:Insertion of MoO3 oxide in the mixed Borophosphate Glass network has been analyzed for the first time by advanced magnetic resonance spectroscopies. For the first time, the xMoO3-(100-x)(50PbO-10BO2O3-40P2O5) composition line has been investigated by 1D (11B, 31P, 95Mo) and 2D-correlation NMR (11B DQ-SQ, 11B(31P) D-HMQC) at high magnetic field (18.8 T). The set of data allowed for analyzing both local and medium range orders and identifying the modifications in the BOB and/or BOP mixing induced by the MoO3 insertion. In a second step, continuous wave EPR has been used to detect the presence of Mo5+ ions, resulting from partial reduction of Mo6+ during the melting stage, and the chemical environment around the Mo5+ species has been documented for the first time by pulsed EPR technique (HYSCORE). Altogether, the data contribute to a better understanding of the Glass network modifications induced by the MoO3 insertion, including the nonlinear evolution of the Glass transition temperature that has been explained by a modification of the Glass network nature.
-
Effect of germanium oxide on the structure and properties of lithium Borophosphate Glasses
Journal of Non-Crystalline Solids, 2013Co-Authors: Petr Mošner, Ladislav Koudelka, Lionel Montagne, Bertrand Revel, Maryna Vorokhta, Kristina Sklepić, Andrea Moguš-milankovićAbstract:Abstract Lithium Borophosphate Glasses with addition of germanium oxide were studied along the compositional series (100 − x)[0.5Li2O–0.1B2O3–0.4P2O5]–xGeO2, with x = 0–25 mol.%. Their properties (density, Glass transition temperature, coefficient of thermal expansion, chemical durability) were measured and their structure was studied by 31P and 11B MAS NMR spectroscopy and Raman spectroscopy. The addition of GeO2 to the parent Borophosphate Glass results in an increase of their Glass transition temperature, while their chemical durability only slightly decreases. 31P MAS NMR and Raman spectra reflect the depolymerization of phosphate chains by the incorporation of GeOn polyhedra. 11B MAS NMR spectra reveal the formation of mixed structural units B(OP)3(OGe) in the Borophosphate Glasses and the decomposition of 11B MAS NMR spectra brings quantitative data on the number of BO3 and B(OP)3(OGe) structural units. A small amount of BO3 trigonal units is formed in the Glasses as well.
-
Thermal studies of ZnO–B2O3–P2O5–TeO2 Glasses
Journal of Thermal Analysis and Calorimetry, 2011Co-Authors: Petr Mošner, Ladislav Koudelka, Kateřina Vosejpková, Ludvík BenešAbstract:The effect of TeO2 additions on the thermal behaviour of zinc Borophosphate Glasses were studied in the compositional series (100 − x)[0.5ZnO–0.1B2O3–0.4P2O5]–xTeO2 by differential scanning calorimetry, thermodilatometry and heating microscopy thermal analysis. The addition of TeO2 to the starting Borophosphate Glass resulted in a linear increase of Glass transition temperature and dilatometric softening temperature, whereas the thermal expansion coefficient decreased. Most of Glasses crystallize under heating within the temperature range of 440–640 °C. The crystallization temperature steeply decreases with increasing TeO2 content. The lowest tendency towards crystallization was observed for the Glasses containing 50 and 60 mol% TeO2. X-ray diffraction analysis showed that major compounds formed by annealing of the Glasses were Zn2P2O7, BPO4 and α-TeO2. Annealing of the powdered 50ZnO–10B2O3–40P2O5 Glass leads at first to the formation of an unknown crystalline phase, which is gradually transformed to Zn2P2O7 and BPO4 during subsequent heating.
-
Structure and properties of ZnO–B2O3–P2O5–TeO2 Glasses
Materials Chemistry and Physics, 2010Co-Authors: Petr Mošner, Ladislav Koudelka, Kateřina Vosejpková, Lionel Montagne, Bertrand RevelAbstract:Abstract Zinc Borophosphate Glasses doped with TeO 2 were studied in the compositional series (100 − x )[0.5ZnO–0.1B 2 O 3 –0.4P 2 O 5 ]– x TeO 2 in a broad concentration range of x = 0–80 mol% TeO 2 . The structure of the Glasses was studied by Raman and IR spectroscopy and by 31 P and 11 B MAS NMR spectroscopy. According to the Raman and IR spectra, TeO 2 is incorporated in the structural network in the form of TeO 3 , TeO 3+1 and TeO 4 structural units. The ratio of TeO 4 /TeO 3 increases with increasing TeO 2 content in the Glasses. The incorporation of TeO x units into the Glass network is associated with the depolymerisation of phosphate chains, as revealed by Raman spectroscopy. The incorporation of TeO 2 modifies also the coordination of boron atoms, where B(OP) 4 structural units are gradually replaced by B(OP) 4− n (OTe) n units. The addition of TeO 2 to the parent zinc Borophosphate Glass results in a decrease of Glass transition temperature associated with the replacement of stronger P–O and B–O bonds by weaker Te–O bonds. Chemical durability of Glasses reveals a minimum at the Glass containing 10 mol% TeO 2 , but with further additions of TeO 2 it improves and the Glasses with a high TeO 2 content reveal better durability than the parent zinc Borophosphate Glass.
Rosli Hussin - One of the best experts on this subject based on the ideXlab platform.
-
Luminescence Behavior of Dy3+ Ions in Calcium Sulfo Borophosphate Glass for White Leds
Indian Journal of Science and Technology, 2016Co-Authors: Y. A. Yamusa, Rosli Hussin, Wan Nurulhuda Wan Shamsuri, S. A. Dalhatu, Aliyu M. AliyuAbstract:Objectives: To Determine the optical properties of Glass by means of ultraviolet, visible and luminescence spectroscopy. Methods/Analysis: Different concentrations of dysprosiumdopedcalcium sulfoBorophosphate (CSBP) Glasses were produced by the melt quenching method and characterized through absorption, excitation and luminescence spectroscopy and its Glassy form was ascertain by XRD. Findings: The emission spectrum of calcium sulfo Borophosphate doped Dy3+ Glasses displays bands at 482 nm (blue) and 572 nm (yellow) underneath excitation 350 nm, which agree to the transitions of 4F9/2→6H15/2 and 4F9/2→6H13/2 of Dy3+ respectively. The spectrum of the excitation for 572 nm emission takes numerous bands at 321 nm, 347 nm, 386 nm, 422 nm, 449 nm and 470 nm, which is in correspondence with the ultraviolet light emitting diode (320–410 nm) and blue light emitting (450–470 nm). Application: The findings show that calcium sulfo Borophosphate doped with Dy3+ Glasses could be certainly used as white LEDs.
-
Luminescence properties of Eu3+ and Dy3+ doped magnesium tellurite Borophosphate Glass
Materials Science Forum, 2016Co-Authors: Siti Maisarah Aziz, Rosli HussinAbstract:The luminescence properties of rare earth in Glass are interesting to study and being one of attractive properties in development of laser. A series of Eu3+/Dy3+ co-doped magnesium tellurite Borophosphate Glass has been prepared with nominal composition 50B2O3-15P2O5-25MgO-10TeO2. The amorphous phases of the sample were characterized using X-ray diffraction pattern and the presence of a broad hunch shows that the sample in an amorphous state. For Eu3+/Dy3+ co-doped Borophosphate Glass sample of consist five peaks where Eu3+ emission were located at 611 nm, 662 nm and 699 nm due to the transition of 5D0-7FJ ( J = 2, 3, 4) while the Dy3+ emission is due to transition 4F9/2-5HJ/2 (J = 15 and 13). Furthermore, Glass sample showed exponential decay curve and lifetime for Glass sample is determined.
-
Study of structural and luminescence properties of lead lithium Borophosphate Glass system doped with Ti ions
Sains Malaysiana, 2014Co-Authors: T. Q. Leow, Pau Ming Leong, Tien Yew Eeu, Zuhairi Ibrahim, Rosli HussinAbstract:Study of a series of lead lithium Borophosphate Glass samples was performed to determine the structural and luminescence properties. The Glass samples containing the composition of 20PbO-xLi(2)O-30B(2)O(3)-(50-x)P2O5-2TiO(2) (where x = 0, 5, 10, 15, 20) system were prepared using melt-quenching technique. The PbO-Li2O-B2O3-P2O5-TiO2 samples were investigated for structural properties using Fourier transform infrared and photoluminescence spectroscopy for studies of luminescence properties. The results from FT-IR showed the presence of trigonal and tetrahedral PO4, PO3, BO4 and BO3 groups within the host network structure. The samples exhibit luminescence emission centered at 420, 482 and 496 nm when excited at 300 nm wavelength. The emission peak at 420 nm were assigned to F center emission and charge-transfer transition of Ti4+ ions. The results showed that emission intensity was dependent on lithium contents in Ti-doped lead lithium Borophosphate Glass composition.
-
Luminescence Properties of Transition Metal and Rare Earth Doped Cadmium Lead Borophosphate Glass
Advanced Materials Research, 2014Co-Authors: Tien Yew Eeu, Xie Guan Pang, T. Q. Leow, Ibrahim Zuahiri, Rosli HussinAbstract:Series of rare earth doped Cadmium Lead Borophosphate Glass were prepared using melt quenching technique and their luminescence properties were studied. Raw materials were mixed and preheat for 30 minutes, melted for 10 minutes without annealing process. With the composition of 30CdO:20PbO:10B2O3:40P2O5 host Glass, 1 mol% of Neodymium Oxide, Ferum Oxide, Titanium Oxide and Yttrium Oxide were doped as activator to study the luminescence effect using Photoluminescence (PL) and Ultraviolet-Visible (UV-Vis) spectrophotometer. By exciting the samples at different wavelength (200-900 nm), the excitation and emission profile were obtained and analyzed to study the energy transfer process. Referring to the spectrum obtained, selected samples were co-doped among each other to obtain desired luminescence properties. Energy level diagram were plotted to discuss and explain the emission transition and mechanism. UV-Visible spectroscopy results reveal the absorption wavelength of samples for targeted application as band filter. Physical properties such as chemical stability and color of the samples were recorded to correlate with PL and UV-Vis result.
-
Structural and luminescence properties of Fe3+ doped antimony lead Borophosphate Glass
Sains Malaysiana, 2014Co-Authors: Leong Pau Ming, Zuhairi Ibrahim, Eeu Tien Yew, Leow Ting Qiao, Pang Xie Guan, Rosli HussinAbstract:Structural and luminescence properties of Borophosphate Glasses with different modifier doped with transition metal ions have been investigated in this study. The Glass sample from the series of xPb(3)O(4):0.2Sb(2)O(3):0.3B(2)O(3):(0.5-x)P2O5 and ySb(2)O(3):0.2Pb(3)O(4):(0.5-y)B2O3:0.3P(2)O(5) where 0
Ladislav Koudelka - One of the best experts on this subject based on the ideXlab platform.
-
Insertion of MoO3 in Borophosphate Glasses Investigated by Magnetic Resonance Spectroscopies
The Journal of Physical Chemistry C, 2016Co-Authors: Grégory Tricot, K. Ben Tayeb, Ladislav Koudelka, Petr Mošner, Hervé VezinAbstract:Insertion of MoO3 oxide in the mixed Borophosphate Glass network has been analyzed for the first time by advanced magnetic resonance spectroscopies. For the first time, the xMoO3-(100-x)(50PbO-10B2O3-40P2O5) composition line has been investigated by 1D (11B, 31P, 95Mo) and 2D-correlation NMR (11B DQ-SQ, 11B(31P) D-HMQC) at high magnetic field (18.8 T). The set of data allowed for analyzing both local and medium range orders and identifying the modifications in the BOB and/or BOP mixing induced by the MoO3 insertion. In a second step, continuous wave EPR has been used to detect the presence of Mo5+ ions, resulting from partial reduction of Mo6+ during the melting stage, and the chemical environment around the Mo5+ species has been documented for the first time by pulsed EPR technique (HYSCORE). Altogether, the data contribute to a better understanding of the Glass network modifications induced by the MoO3 insertion, including the nonlinear evolution of the Glass transition temperature that has been explain...
-
Insertion of MoO3 in Borophosphate Glasses investigated by magnetic resonance spectroscopies
Journal of Physical Chemistry C, 2016Co-Authors: Grégory Tricot, Ladislav Koudelka, Petr Mošner, K. Ben Tayeb, Hervé VezinAbstract:Insertion of MoO3 oxide in the mixed Borophosphate Glass network has been analyzed for the first time by advanced magnetic resonance spectroscopies. For the first time, the xMoO3-(100-x)(50PbO-10BO2O3-40P2O5) composition line has been investigated by 1D (11B, 31P, 95Mo) and 2D-correlation NMR (11B DQ-SQ, 11B(31P) D-HMQC) at high magnetic field (18.8 T). The set of data allowed for analyzing both local and medium range orders and identifying the modifications in the BOB and/or BOP mixing induced by the MoO3 insertion. In a second step, continuous wave EPR has been used to detect the presence of Mo5+ ions, resulting from partial reduction of Mo6+ during the melting stage, and the chemical environment around the Mo5+ species has been documented for the first time by pulsed EPR technique (HYSCORE). Altogether, the data contribute to a better understanding of the Glass network modifications induced by the MoO3 insertion, including the nonlinear evolution of the Glass transition temperature that has been explained by a modification of the Glass network nature.
-
Effect of germanium oxide on the structure and properties of lithium Borophosphate Glasses
Journal of Non-Crystalline Solids, 2013Co-Authors: Petr Mošner, Ladislav Koudelka, Lionel Montagne, Bertrand Revel, Maryna Vorokhta, Kristina Sklepić, Andrea Moguš-milankovićAbstract:Abstract Lithium Borophosphate Glasses with addition of germanium oxide were studied along the compositional series (100 − x)[0.5Li2O–0.1B2O3–0.4P2O5]–xGeO2, with x = 0–25 mol.%. Their properties (density, Glass transition temperature, coefficient of thermal expansion, chemical durability) were measured and their structure was studied by 31P and 11B MAS NMR spectroscopy and Raman spectroscopy. The addition of GeO2 to the parent Borophosphate Glass results in an increase of their Glass transition temperature, while their chemical durability only slightly decreases. 31P MAS NMR and Raman spectra reflect the depolymerization of phosphate chains by the incorporation of GeOn polyhedra. 11B MAS NMR spectra reveal the formation of mixed structural units B(OP)3(OGe) in the Borophosphate Glasses and the decomposition of 11B MAS NMR spectra brings quantitative data on the number of BO3 and B(OP)3(OGe) structural units. A small amount of BO3 trigonal units is formed in the Glasses as well.
-
Thermal studies of ZnO–B2O3–P2O5–TeO2 Glasses
Journal of Thermal Analysis and Calorimetry, 2011Co-Authors: Petr Mošner, Ladislav Koudelka, Kateřina Vosejpková, Ludvík BenešAbstract:The effect of TeO2 additions on the thermal behaviour of zinc Borophosphate Glasses were studied in the compositional series (100 − x)[0.5ZnO–0.1B2O3–0.4P2O5]–xTeO2 by differential scanning calorimetry, thermodilatometry and heating microscopy thermal analysis. The addition of TeO2 to the starting Borophosphate Glass resulted in a linear increase of Glass transition temperature and dilatometric softening temperature, whereas the thermal expansion coefficient decreased. Most of Glasses crystallize under heating within the temperature range of 440–640 °C. The crystallization temperature steeply decreases with increasing TeO2 content. The lowest tendency towards crystallization was observed for the Glasses containing 50 and 60 mol% TeO2. X-ray diffraction analysis showed that major compounds formed by annealing of the Glasses were Zn2P2O7, BPO4 and α-TeO2. Annealing of the powdered 50ZnO–10B2O3–40P2O5 Glass leads at first to the formation of an unknown crystalline phase, which is gradually transformed to Zn2P2O7 and BPO4 during subsequent heating.
-
Structure and properties of ZnO–B2O3–P2O5–TeO2 Glasses
Materials Chemistry and Physics, 2010Co-Authors: Petr Mošner, Ladislav Koudelka, Kateřina Vosejpková, Lionel Montagne, Bertrand RevelAbstract:Abstract Zinc Borophosphate Glasses doped with TeO 2 were studied in the compositional series (100 − x )[0.5ZnO–0.1B 2 O 3 –0.4P 2 O 5 ]– x TeO 2 in a broad concentration range of x = 0–80 mol% TeO 2 . The structure of the Glasses was studied by Raman and IR spectroscopy and by 31 P and 11 B MAS NMR spectroscopy. According to the Raman and IR spectra, TeO 2 is incorporated in the structural network in the form of TeO 3 , TeO 3+1 and TeO 4 structural units. The ratio of TeO 4 /TeO 3 increases with increasing TeO 2 content in the Glasses. The incorporation of TeO x units into the Glass network is associated with the depolymerisation of phosphate chains, as revealed by Raman spectroscopy. The incorporation of TeO 2 modifies also the coordination of boron atoms, where B(OP) 4 structural units are gradually replaced by B(OP) 4− n (OTe) n units. The addition of TeO 2 to the parent zinc Borophosphate Glass results in a decrease of Glass transition temperature associated with the replacement of stronger P–O and B–O bonds by weaker Te–O bonds. Chemical durability of Glasses reveals a minimum at the Glass containing 10 mol% TeO 2 , but with further additions of TeO 2 it improves and the Glasses with a high TeO 2 content reveal better durability than the parent zinc Borophosphate Glass.
A. Suresh Kumar - One of the best experts on this subject based on the ideXlab platform.
-
Fluorescence Features of Dy3+ Doped PbO-Bi2O3 Borophosphate Glasses
Asian Journal of Research in Chemistry, 2014Co-Authors: Y.n.ch. Ravi Babu, Sunita Prasad, M. N. Kiran Kumar, A. Suresh KumarAbstract:The heavy metal oxide lead bismuth magnesium Borophosphate Glass systems (LBMBPD)dysprosium ions doped with the molar compositions of (50-x) PbO -x Bi2O3-25MgHPO4-24B2O3-1Dy2O3 (where x = 10, 20, 30, and 40 mol %) were prepared using conventional melt quenching technique. The spectral data from the optical absorption photoluminescence were utilized to evaluate various spectroscopic parameters. The Judd-Ofelt parameterization employed reflects the covalency and vibration frequencies of the ligands with dysprosium ions. The radiative parameters such as radiative transition probabilities (A), the total radiative transitional probabilities (AT), radiative life times (τR), branching ratios (β) and absorption cross sections (□) were computed for certain lasing levels. The emission cross sections (σe) for the significant lasing transitions 4F9/2→ 6H13/2 and 4F9/2 → 6H15/2 evaluated from the photoluminescence spectra were reported. The radiative properties thus obtained in our investigations reflect their potentialities as good lasing candidates.
-
Photoluminescence features of Ho3+ ion doped PbO–Bi2O3 Borophosphate Glass systems
Journal of Luminescence, 2013Co-Authors: Y.n.ch. Ravi Babu, P. Sree Ramnaik, A. Suresh KumarAbstract:Abstract Spectroscopic and physical properties of Ho3+ doped multi-component Glass systems in varying molar compositions of xBi2O3–(50−x) PbO–25MgHPO4–24B2O3–1Ho2O3 (where x=10, 20, 30, and 40) have been investigated. Optical absorption spectra have been used to determine Racah coefficients (E1, E2 and E3), Slater Condon parameters (F2, F4 and F6), spin–orbit coupling parameters (ξ4f), and configuration interaction parameters (α and β). The ratios of E1/E3 and E2/E3 do not deviate much from the hydrogenic ratios. Optical basicity of the Glasses is estimated. The Judd–Ofelt parameters (Ω2, Ω4 and Ω6) were computed from the intensities of the energy levels. The radiative lifetimes (τR), branching ratios (β) and absorption cross sections (σa) were evaluated for the lasing levels 5I8→5G6, 5F2, 5F3, 5F4, 5F5, 5I6, and 5I7. The emission cross sections (σe) for the significant lasing transitions 5F4→5I8, 5F5→5I8 and 5S2→5I7 evaluated from the photoluminescence spectra are reported. The lasing potencies estimated for all the Glasses under study indicate lasing action in the cw as well as in pulsed regime.
-
Spectral studies of Erbium doped heavy metal Borophosphate Glass systems
Physica B: Condensed Matter, 2012Co-Authors: Y.n.ch. Ravi Babu, P. Sree Ram Naik, K. Vijaya Kumar, Sunita Prasad, A. Suresh KumarAbstract:Abstract The ternary lead bismuth magnesium Borophosphate Glass system (LBMBPE) with molar concentrations of (50– x ) PbO– x Bi 2 O 3 –25MgHPO 4 –24B 2 O 3 –1Er 2 O 3 ( x =10, 20, 30 and 40) was prepared using Melt quenching technique. The amorphous nature of these Glass samples were confirmed with XRD studies, The spectral data from the optical absorption studies was employed to compute the spectroscopic parameters such as Racah coefficients ( E 1 , E 2 and E 3 ), spin–orbit coupling (ξ 4 f ), configuration interaction factor ( α ) and Judd–Ofelt intensity parameters ( Ω λ , λ =2, 4 and 6). The IR spectra exhibit the presence of vibrational modes of phosphates, borate radicals, bismuth, lead and magnesium ions. The Judd–Ofelt parameterization indicates the covalency and vibrationonic frequencies of the ligands with rare earth ions. The radiative parameters such as radiative transition probabilities (A), the total radiative transitional probabilities ( A T ), radiative life times ( τ R ), branching ratios ( β ) and absorption cross sections (∑) were computed for certain lasing levels. The effect of compositional changes on the optical band gap is also reported. The Glass systems thus developed indicate their potential lasing candidature.
-
Spectral investigations of Sm3+ doped lead bismuth magnesium Borophosphate Glasses
Journal of Quantitative Spectroscopy and Radiative Transfer, 2012Co-Authors: Y.n.ch. Ravi Babu, P. Sree Ram Naik, K. R. Vijaya Kumar, N. Rajesh Kumar, A. Suresh KumarAbstract:The multicomponent lead bismuth magnesium Borophosphate Glass systems (LBMBPS) doped with Samarium ions with the molar compositions of (50−x)PbOxBi2O325MgHPO424B2O31Sm2O3 (where x=10, 20, 30, and 40) were fabricated using conventional melt quenching technique. The amorphous nature of these Glass samples was confirmed with XRD studies. The spectral data from the optical absorption studies were employed to compute various spectroscopic parameters such as Judd–Ofelt intensity parameters. The Judd–Ofelt parameterization employed reflects the covalency and vibration frequencies of the ligands with Samarium ions. The radiative parameters such as radiative transition probabilities (A), the total radiative transitional probabilities (AT), radiative life times (τR), branching ratios (β) and absorption cross sections (Σ) were computed for certain lasing levels. The Glass systems thus developed indicate their potential lasing candidature. The emission cross sections (σE) for the significant lasing transitions 4G5/2→6H5/2, 4G5/2→6H7/2, and 4G5/2→6H9/2 evaluated from the photoluminescence spectra were reported. The radiative properties obtained in our investigations suggest their lasing candidature.
-
Spectral studies on Cr3+ ions doped in sodium–lead Borophosphate Glasses
Physica B: Condensed Matter, 2011Co-Authors: Nagulapati Kiran, A. Suresh Kumar, C.r. Kesavulu, J.l. RaoAbstract:Abstract Electron paramagnetic resonance (EPR), optical absorption and emission spectra of Cr3+ ions doped in (30−x) (NaPO3)6+30PbO+40B2O3+xCr2O3 (x=0.5, 2.0, 3.0, 4.0 and 5.0 mol%) Glasses have been studied. The EPR spectra exhibit resonance signals with effective g values at g≈4.55 and g≈1.97. The EPR spectra of x=3.0 mol% of Cr2O3 in sodium–lead Borophosphate Glass sample were studied at various temperatures (295–123 K). The intensity of the resonance signals increases with decrease in temperature. The optical absorption spectrum exhibits four bands characteristic of Cr3+ ions in octahedral symmetry. From the analysis of the bands, the crystal-field parameter Dq and the Racah interelectronic repulsion parameters B and C have been evaluated. The emission spectrum exhibit one broad band characteristic of Cr3+ ions in octahedral symmetry. This band has been assigned to the transition 4T2g (F)→4A2g (F). Correlating EPR and optical data, the molecular bonding coefficient (α) has been evaluated.
Hyo Jin Seo - One of the best experts on this subject based on the ideXlab platform.
-
temperature dependent 5d0 7f0 luminescence of sm2 ions doped in alkaline earth Borophosphate Glass
Journal of the American Ceramic Society, 2010Co-Authors: Jiayu Wang, Yanlin Huang, Hyo Jin SeoAbstract:Sm 2 0 3 -doped SrO―BaO―P 2 O 5 ―B 2 O 3 Glass was prepared by a conventional melt quenching method in air. The Glass was irradiated using X-rays to reduce the Sm 3+ ions to Sm 2+ ions. After the X-ray irradiation, photoluminescence studies at different temperatures showed that the conversion of Sm 3+ to Sm 2+ could be realized in this alkaline earth Borophosphate Glass. The luminescence of the Sm 2+ ions showed a strong dependence on temperature. Photo-stability of Sm 2+ ion was evaluated using a photo-bleaching method. Thermo-luminescence and life-time measurements were also investigated. The results of this study could be useful for understanding the reduction mechanism of Sm 3+ ions to Sm 2+ ions in alkaline earth Borophosphate Glass.
-
Temperature-Dependent 5D0→7F0 Luminescence of Sm2+ Ions Doped in Alkaline Earth Borophosphate Glass
Journal of the American Ceramic Society, 2010Co-Authors: Jiayu Wang, Yanlin Huang, Hyo Jin SeoAbstract:Sm 2 0 3 -doped SrO―BaO―P 2 O 5 ―B 2 O 3 Glass was prepared by a conventional melt quenching method in air. The Glass was irradiated using X-rays to reduce the Sm 3+ ions to Sm 2+ ions. After the X-ray irradiation, photoluminescence studies at different temperatures showed that the conversion of Sm 3+ to Sm 2+ could be realized in this alkaline earth Borophosphate Glass. The luminescence of the Sm 2+ ions showed a strong dependence on temperature. Photo-stability of Sm 2+ ion was evaluated using a photo-bleaching method. Thermo-luminescence and life-time measurements were also investigated. The results of this study could be useful for understanding the reduction mechanism of Sm 3+ ions to Sm 2+ ions in alkaline earth Borophosphate Glass.