Eren Karsu | Celal Bayar University (original) (raw)
Papers by Eren Karsu
Inorganica Chimica Acta, 1990
The crystal structure of Tb(NO& 6H,O IS determined at 295 K from X-ray diffraction measurements T... more The crystal structure of Tb(NO& 6H,O IS determined at 295 K from X-ray diffraction measurements The compound crystalhzes m the trlclmlc space group Pl (ITC No 2) with Z=2 Cell parameters are a = 9 095(7), b = 11 600(6), c =6 705(4) A, a=91 14(4), p=llO 79(5), y=70 14(S)", V=617 9(6) A3, Dcalc = 2 44 g cm-', D,,,, = 2 41 g cm-' The final R, was 0 036 for 2165 umque reflections The Tb(II1) 1s decacoordmated, being bonded to four water molecules and three bldentate nitrate Ions The coordmatton polyhedron 1s a distorted 40A,6B-extended dodecahedron One mtrate Ion IS asymmetrically bonded, wjth one Tb-0 distance 0 22 A longer than the other The luminescent properties of Eu(II1) and Tb(II1) m [Ln(NO,),(X,O),] 2X20, X= H, D are reported The number of water molecules directly coordinated to the metal ion are estimated from hfetlme measurements These numbers largely exceed the expected value of 4 This fact, together with analogous results reported for the chloride hexahydrates, tend to demonstrate that this method should be used with care
Journal of Luminescence, 2017
In the present work flame spray pyrolysis synthesis and characterization of the nano-scale phosph... more In the present work flame spray pyrolysis synthesis and characterization of the nano-scale phosphors; M′-YTaO 4 and M′-Y(Ta 0.85 Nb 0.15)O 4 have been studied for the first time. Phase and elemental analysis of the produced nanophosphors were carried out by X-Ray Diffraction (XRD) and X-Ray Photoelectron Spectroscopy (XPS) measurements, respectively. The surface morphology and particle size of the nanophosphors were identified using scanning electron microscopy (SEM). The XRD results reveal that the nanophosphors have monoclinic M′-YTaO 4 and M′-Y(Ta 0.85 Nb 0.15)O 4 phases belonging to the presence of M´-form of fergusonite structure. The particle sizes of the nanophosphors were found to be in the range of 50-100 nm. The spectroscopic characterization was performed by both radioluminescence (RL) and thermally stimulated luminescence (TSL) measurements after exposure to X-ray irradiation. Also, photoluminescence and decay times were investigated under UV excitation. The nanophosphors can be concluded as appropriate emissive materials for imaging, display and scintillator applications due to the efficient photoluminescence, moderate radioluminescence (RL) and thermally stimulated luminescence characteristics.
Both Li2B4O7: Cu, In and MgB4O7: Dy, Na are well established thermoluminescence (T L) materials. ... more Both Li2B4O7: Cu, In and MgB4O7: Dy, Na are well established thermoluminescence (T L) materials. Until now, many scientists focused on these materials by studying many properties of these luminescence mate rials but still the irradiation temperature response of e ith r material hasn’t been studied. Irradiation te mperature response could be a crucial parameter in many appli cations, such as dating, reactor core dosimetry, sp ace research, temperature exposure monitoring, high dos e dosimetry, and in space, polar and hot desert reg ion TL studies. Moreover, Irradiation temperature resp onse enables us to better understand the TL phenomenon. In this study both the irradiation tem p rature and post irradiation annealing responses o f the aforementioned artificial luminescence materials we re investigated in detail.
ABSTRACT The spectroscopic characterization down to 10 K was performed for undoped and Ln doped C... more ABSTRACT The spectroscopic characterization down to 10 K was performed for undoped and Ln doped CaLa4(SiO4)3O (Ln=Eu3+, Eu2+, Ce3+, Dy3+, Tb3+). Based on the experimental and literature data the scheme was constructed showing the vacuum referred binding energy (VRBE) of electrons in lanthanide states and band states in CaLa4(SiO4)3O. This scheme predicts that co-doping with Eu2+ and Ln3+ (Ln=Dy, Nd) will induce afterglow. Thermoluminescence and afterglow were indeed measured and compared with a commercial SrAl2O4:Eu, Dy afterglow phosphor.
In the present work flame spray pyrolysis synthesis and characterization of the nano-scale phosph... more In the present work flame spray pyrolysis synthesis and characterization of the nano-scale phosphours; M′-YTaO4 and M′-Y(Ta0.85Nb0.15)O4 have been studied for the first time. Phase and elemental analysis of the produced nanophosphors were carried out by X-Ray Diffraction (XRD) and X-Ray Photoelectron Spectroscopy (XPS) measurements, respectively. The surface morphology and particle size of the nanophosphors were identified using scanning electron microscopy (SEM). The XRD results reveal that the nanophosphors have monoclinic M′-YTaO4 and M′-Y(Ta0.85Nb0.15)O4 phases belonging to the presence of M´-form of fergusonite structure. The particle sizes of the nanophosphors were found to be in the range of 50–100 nm. The spectroscopic characterization was performed by both radioluminescence (RL) and thermally stimulated luminescence (TSL) measurements after exposure to X-ray irradiation. Also, photoluminescence and decay times were investigated under UV excitation. The nanophosphors can be concluded as appropriate emissive materials for imaging, display and scintillator applications due to the efficient photoluminescence, moderate radioluminescence (RL) and thermally stimulated luminescence characteristics.
Journal of Luminescence, 2015
The spectroscopic characterization down to 10 K was performed for undoped and Ln doped CaLa 4 (Si... more The spectroscopic characterization down to 10 K was performed for undoped and Ln doped CaLa 4 (SiO 4 ) 3 O (Ln ¼Eu 3 þ , Eu 2 þ , Ce 3 þ , Dy 3 þ , Tb 3 þ ). Based on the experimental and literature data the scheme was constructed showing the vacuum referred binding energy (VRBE) of electrons in lanthanide states and band states in CaLa 4 (SiO 4 ) 3 O. This scheme predicts that co-doping with Eu 2 þ and Ln 3 þ (Ln¼ Dy, Nd) will induce afterglow. Thermoluminescence and afterglow were indeed measured and compared with a commercial SrAl 2 O 4 :Eu, Dy afterglow phosphor.
Journal of Physics D: Applied Physics, 2006
Dosimeters of MgB4O7 doped with Dy and Na have many valuable features such as high sensitivity, t... more Dosimeters of MgB4O7 doped with Dy and Na have many valuable features such as high sensitivity, tissue equivalence, low fading, non-requirement of annealing and insensitivity to light. Thermoluminescence studies of Dy and Na doped MgB4O7 samples showed that a glow emission peaked at about 195 °C. In this study, the trapping parameters associated with the main dosimetric peak, namely at 195 °C, of Dy and Na doped MgB4O7 are investigated. Isothermal luminescence decay, glow curve shape, initial rise (linear regression) and Tm - Tstop methods were used. We report the results on the kinetic behaviour and activation energy determination of the peak occurring at 195 °C with a moderate heating rate of 2 °C s-1. The average activation energies obtained by the isothermal luminescence decay method, glow curve shape method and initial rise method are calculated to be 1.03 eV, 0.95 eV and 0.89 eV, respectively. The methods mentioned above indicate that the dosimetric peak may consist of one or more second-order components. The frequency factors obtained by the three methods are 3.5 × 1010 s-1, 1.6 × 109 s-1 and 3.4 × 108 s-1, respectively. Results obtained using all these methods are compared and discussed.
Journal of Luminescence, 2011
Yttrium tantalate (YTaO 4 ), yttrium niobium-tantalate (YTaNbO 4 ), yttrium niobate (YNbO 4 ), eu... more Yttrium tantalate (YTaO 4 ), yttrium niobium-tantalate (YTaNbO 4 ), yttrium niobate (YNbO 4 ), europium and terbium activated yttrium tantalate (YTaO 4 :Eu, YTaO 4 :Tb) and europium activated yttrium niobate (YNbO 4 :Eu) phosphors were prepared by solid-state reaction, from a homogeneous mixture consisting of SO 4 as flux. Photoluminescence (PL), thermally stimulated luminescence (TSL), X-ray diffraction (XRD) and scanning electron microscopy (SEM) of yttrium tantalate based phosphors are reported. In the present study TSL characteristics of these phosphors were first investigated and reported after exposure to beta, UV (311 nm) and X-ray radiations.
Journal of Luminescence, 2015
ABSTRACT The spectroscopic characterization down to 10 K was performed for undoped and Ln doped C... more ABSTRACT The spectroscopic characterization down to 10 K was performed for undoped and Ln doped CaLa4(SiO4)3O (Ln=Eu3+, Eu2+, Ce3+, Dy3+, Tb3+). Based on the experimental and literature data the scheme was constructed showing the vacuum referred binding energy (VRBE) of electrons in lanthanide states and band states in CaLa4(SiO4)3O. This scheme predicts that co-doping with Eu2+ and Ln3+ (Ln=Dy, Nd) will induce afterglow. Thermoluminescence and afterglow were indeed measured and compared with a commercial SrAl2O4:Eu, Dy afterglow phosphor.
Inorganica Chimica Acta, 1990
The crystal structure of Tb(NO& 6H,O IS determined at 295 K from X-ray diffraction measurements T... more The crystal structure of Tb(NO& 6H,O IS determined at 295 K from X-ray diffraction measurements The compound crystalhzes m the trlclmlc space group Pl (ITC No 2) with Z=2 Cell parameters are a = 9 095(7), b = 11 600(6), c =6 705(4) A, a=91 14(4), p=llO 79(5), y=70 14(S)", V=617 9(6) A3, Dcalc = 2 44 g cm-', D,,,, = 2 41 g cm-' The final R, was 0 036 for 2165 umque reflections The Tb(II1) 1s decacoordmated, being bonded to four water molecules and three bldentate nitrate Ions The coordmatton polyhedron 1s a distorted 40A,6B-extended dodecahedron One mtrate Ion IS asymmetrically bonded, wjth one Tb-0 distance 0 22 A longer than the other The luminescent properties of Eu(II1) and Tb(II1) m [Ln(NO,),(X,O),] 2X20, X= H, D are reported The number of water molecules directly coordinated to the metal ion are estimated from hfetlme measurements These numbers largely exceed the expected value of 4 This fact, together with analogous results reported for the chloride hexahydrates, tend to demonstrate that this method should be used with care
Journal of Luminescence, 2017
In the present work flame spray pyrolysis synthesis and characterization of the nano-scale phosph... more In the present work flame spray pyrolysis synthesis and characterization of the nano-scale phosphors; M′-YTaO 4 and M′-Y(Ta 0.85 Nb 0.15)O 4 have been studied for the first time. Phase and elemental analysis of the produced nanophosphors were carried out by X-Ray Diffraction (XRD) and X-Ray Photoelectron Spectroscopy (XPS) measurements, respectively. The surface morphology and particle size of the nanophosphors were identified using scanning electron microscopy (SEM). The XRD results reveal that the nanophosphors have monoclinic M′-YTaO 4 and M′-Y(Ta 0.85 Nb 0.15)O 4 phases belonging to the presence of M´-form of fergusonite structure. The particle sizes of the nanophosphors were found to be in the range of 50-100 nm. The spectroscopic characterization was performed by both radioluminescence (RL) and thermally stimulated luminescence (TSL) measurements after exposure to X-ray irradiation. Also, photoluminescence and decay times were investigated under UV excitation. The nanophosphors can be concluded as appropriate emissive materials for imaging, display and scintillator applications due to the efficient photoluminescence, moderate radioluminescence (RL) and thermally stimulated luminescence characteristics.
Both Li2B4O7: Cu, In and MgB4O7: Dy, Na are well established thermoluminescence (T L) materials. ... more Both Li2B4O7: Cu, In and MgB4O7: Dy, Na are well established thermoluminescence (T L) materials. Until now, many scientists focused on these materials by studying many properties of these luminescence mate rials but still the irradiation temperature response of e ith r material hasn’t been studied. Irradiation te mperature response could be a crucial parameter in many appli cations, such as dating, reactor core dosimetry, sp ace research, temperature exposure monitoring, high dos e dosimetry, and in space, polar and hot desert reg ion TL studies. Moreover, Irradiation temperature resp onse enables us to better understand the TL phenomenon. In this study both the irradiation tem p rature and post irradiation annealing responses o f the aforementioned artificial luminescence materials we re investigated in detail.
ABSTRACT The spectroscopic characterization down to 10 K was performed for undoped and Ln doped C... more ABSTRACT The spectroscopic characterization down to 10 K was performed for undoped and Ln doped CaLa4(SiO4)3O (Ln=Eu3+, Eu2+, Ce3+, Dy3+, Tb3+). Based on the experimental and literature data the scheme was constructed showing the vacuum referred binding energy (VRBE) of electrons in lanthanide states and band states in CaLa4(SiO4)3O. This scheme predicts that co-doping with Eu2+ and Ln3+ (Ln=Dy, Nd) will induce afterglow. Thermoluminescence and afterglow were indeed measured and compared with a commercial SrAl2O4:Eu, Dy afterglow phosphor.
In the present work flame spray pyrolysis synthesis and characterization of the nano-scale phosph... more In the present work flame spray pyrolysis synthesis and characterization of the nano-scale phosphours; M′-YTaO4 and M′-Y(Ta0.85Nb0.15)O4 have been studied for the first time. Phase and elemental analysis of the produced nanophosphors were carried out by X-Ray Diffraction (XRD) and X-Ray Photoelectron Spectroscopy (XPS) measurements, respectively. The surface morphology and particle size of the nanophosphors were identified using scanning electron microscopy (SEM). The XRD results reveal that the nanophosphors have monoclinic M′-YTaO4 and M′-Y(Ta0.85Nb0.15)O4 phases belonging to the presence of M´-form of fergusonite structure. The particle sizes of the nanophosphors were found to be in the range of 50–100 nm. The spectroscopic characterization was performed by both radioluminescence (RL) and thermally stimulated luminescence (TSL) measurements after exposure to X-ray irradiation. Also, photoluminescence and decay times were investigated under UV excitation. The nanophosphors can be concluded as appropriate emissive materials for imaging, display and scintillator applications due to the efficient photoluminescence, moderate radioluminescence (RL) and thermally stimulated luminescence characteristics.
Journal of Luminescence, 2015
The spectroscopic characterization down to 10 K was performed for undoped and Ln doped CaLa 4 (Si... more The spectroscopic characterization down to 10 K was performed for undoped and Ln doped CaLa 4 (SiO 4 ) 3 O (Ln ¼Eu 3 þ , Eu 2 þ , Ce 3 þ , Dy 3 þ , Tb 3 þ ). Based on the experimental and literature data the scheme was constructed showing the vacuum referred binding energy (VRBE) of electrons in lanthanide states and band states in CaLa 4 (SiO 4 ) 3 O. This scheme predicts that co-doping with Eu 2 þ and Ln 3 þ (Ln¼ Dy, Nd) will induce afterglow. Thermoluminescence and afterglow were indeed measured and compared with a commercial SrAl 2 O 4 :Eu, Dy afterglow phosphor.
Journal of Physics D: Applied Physics, 2006
Dosimeters of MgB4O7 doped with Dy and Na have many valuable features such as high sensitivity, t... more Dosimeters of MgB4O7 doped with Dy and Na have many valuable features such as high sensitivity, tissue equivalence, low fading, non-requirement of annealing and insensitivity to light. Thermoluminescence studies of Dy and Na doped MgB4O7 samples showed that a glow emission peaked at about 195 °C. In this study, the trapping parameters associated with the main dosimetric peak, namely at 195 °C, of Dy and Na doped MgB4O7 are investigated. Isothermal luminescence decay, glow curve shape, initial rise (linear regression) and Tm - Tstop methods were used. We report the results on the kinetic behaviour and activation energy determination of the peak occurring at 195 °C with a moderate heating rate of 2 °C s-1. The average activation energies obtained by the isothermal luminescence decay method, glow curve shape method and initial rise method are calculated to be 1.03 eV, 0.95 eV and 0.89 eV, respectively. The methods mentioned above indicate that the dosimetric peak may consist of one or more second-order components. The frequency factors obtained by the three methods are 3.5 × 1010 s-1, 1.6 × 109 s-1 and 3.4 × 108 s-1, respectively. Results obtained using all these methods are compared and discussed.
Journal of Luminescence, 2011
Yttrium tantalate (YTaO 4 ), yttrium niobium-tantalate (YTaNbO 4 ), yttrium niobate (YNbO 4 ), eu... more Yttrium tantalate (YTaO 4 ), yttrium niobium-tantalate (YTaNbO 4 ), yttrium niobate (YNbO 4 ), europium and terbium activated yttrium tantalate (YTaO 4 :Eu, YTaO 4 :Tb) and europium activated yttrium niobate (YNbO 4 :Eu) phosphors were prepared by solid-state reaction, from a homogeneous mixture consisting of SO 4 as flux. Photoluminescence (PL), thermally stimulated luminescence (TSL), X-ray diffraction (XRD) and scanning electron microscopy (SEM) of yttrium tantalate based phosphors are reported. In the present study TSL characteristics of these phosphors were first investigated and reported after exposure to beta, UV (311 nm) and X-ray radiations.
Journal of Luminescence, 2015
ABSTRACT The spectroscopic characterization down to 10 K was performed for undoped and Ln doped C... more ABSTRACT The spectroscopic characterization down to 10 K was performed for undoped and Ln doped CaLa4(SiO4)3O (Ln=Eu3+, Eu2+, Ce3+, Dy3+, Tb3+). Based on the experimental and literature data the scheme was constructed showing the vacuum referred binding energy (VRBE) of electrons in lanthanide states and band states in CaLa4(SiO4)3O. This scheme predicts that co-doping with Eu2+ and Ln3+ (Ln=Dy, Nd) will induce afterglow. Thermoluminescence and afterglow were indeed measured and compared with a commercial SrAl2O4:Eu, Dy afterglow phosphor.