Pub Date : 2002-10-01DOI: 10.1080/13642810208220731
D. W. Cooke, B. Bennett, K. Mcclellan, R. Muenchausen, J. Tesmer, C. Wetteland
Abstract Thermally stimulated luminescence and emission spectra of cerium-doped Lu2SiO5 have been measured in the temperature interval 10K ⩽ T ⩽ 310K. Eight glow peaks occur with the most intense peak exhibiting a maximum at 306 K. Data analyses show that the peaks generally obey first-order kinetics with thermal activation energies ranging from 0.085 to 0.907 eV. The relatively short lifetime (160 s) of the intense glow peak at 306 K implies that it does not make a significant contribution to the long-lived room-temperature afterglow routinely observed in this phosphor. Spectral emission of the glow peaks is dominated by Ce3+ de-excitation, although additional emission due to trace amounts of Sm3+ is observed for T < 72 K. Elastic recoil detection measurements in nominally undoped and cerium-doped Lu2SiO5 show that the doped specimen contains 3.5–4.0 times more hydrogen within the first 300 nm of the surface than does the undoped sample. However, spectral emission associated with surface hydrogen defects was not observed. Oxygen vacancies, which trap one or more electrons, are proposed as the most likely defect sites in Lu2SiO5. Perturbations of the six- and seven-oxygen-coordinated sites produce a multipeak glow curve with various activation energies and frequency factors. The glow peaks are intrinsic to the C2/c-structured lattice and are independent of the particular rare-earth dopant ion.
{"title":"Luminescence, emission spectra and hydrogen content of crystalline Lu2SiO5:Ce3+","authors":"D. W. Cooke, B. Bennett, K. Mcclellan, R. Muenchausen, J. Tesmer, C. Wetteland","doi":"10.1080/13642810208220731","DOIUrl":"https://doi.org/10.1080/13642810208220731","url":null,"abstract":"Abstract Thermally stimulated luminescence and emission spectra of cerium-doped Lu2SiO5 have been measured in the temperature interval 10K ⩽ T ⩽ 310K. Eight glow peaks occur with the most intense peak exhibiting a maximum at 306 K. Data analyses show that the peaks generally obey first-order kinetics with thermal activation energies ranging from 0.085 to 0.907 eV. The relatively short lifetime (160 s) of the intense glow peak at 306 K implies that it does not make a significant contribution to the long-lived room-temperature afterglow routinely observed in this phosphor. Spectral emission of the glow peaks is dominated by Ce3+ de-excitation, although additional emission due to trace amounts of Sm3+ is observed for T < 72 K. Elastic recoil detection measurements in nominally undoped and cerium-doped Lu2SiO5 show that the doped specimen contains 3.5–4.0 times more hydrogen within the first 300 nm of the surface than does the undoped sample. However, spectral emission associated with surface hydrogen defects was not observed. Oxygen vacancies, which trap one or more electrons, are proposed as the most likely defect sites in Lu2SiO5. Perturbations of the six- and seven-oxygen-coordinated sites produce a multipeak glow curve with various activation energies and frequency factors. The glow peaks are intrinsic to the C2/c-structured lattice and are independent of the particular rare-earth dopant ion.","PeriodicalId":20016,"journal":{"name":"Philosophical Magazine Part B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79429865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-10-01DOI: 10.1080/13642810208220730
Liuchun Cai, P. Boolchand
Abstract Molecular structure of GexS100-x glasses in the 30 < x < 34 atomic percentage range is examined by Raman scattering, 119Sn Mössbauer spectroscopy, and temperature-modulated differential scanning calorimetry. The results show that the stoichiometric glass with x = 33.33 (T g = 508°C) is chemically disordered. Raman scattering places mode strengths of corner-sharing Ge(S1/2)4 tetrahedra (A), ethane-like Ge2(S1/2)6 units (B), and the distorted rocksalt Ge(S1/6)6 units (C) at approximately 93.4:3.6:3.0 not normalized for mode cross-sections. Mössbauer spectroscopy places the concentration of these units as A : B : C = 76.2:8.8 :15. The drastic reduction in the slope of the glass transition temperature T g with Ge content x coincides with first appearance of these units once x exceeds 32.50, suggesting that these units are demixed and form separate nanophases to lower the global connectivity of the glass network.
摘要采用拉曼散射、119Sn Mössbauer光谱和温度调制差示扫描量热法研究了30 < x < 34原子百分比范围内的GexS100-x玻璃的分子结构。结果表明，x = 33.33 (T g = 508℃)的化学计量玻璃是化学无序的。拉曼散射使共用角的Ge(S1/2)4四面体(A)、类乙烷的Ge2(S1/2)6单位(B)和变形的岩盐Ge(S1/6)6单位(C)的模式强度约为93.4:3.6:3.0，模式截面未归一化。Mössbauer光谱测定这些单位的浓度为A: B: C = 76.2:8.8:15。玻璃化转变温度T g的斜率随Ge含量x的急剧下降，与这些单元在x超过32.50时首次出现一致，这表明这些单元被分解并形成单独的纳米相，从而降低了玻璃网络的整体连连接性。
{"title":"Nanoscale phase separation of GeS2 glass","authors":"Liuchun Cai, P. Boolchand","doi":"10.1080/13642810208220730","DOIUrl":"https://doi.org/10.1080/13642810208220730","url":null,"abstract":"Abstract Molecular structure of GexS100-x glasses in the 30 < x < 34 atomic percentage range is examined by Raman scattering, 119Sn Mössbauer spectroscopy, and temperature-modulated differential scanning calorimetry. The results show that the stoichiometric glass with x = 33.33 (T g = 508°C) is chemically disordered. Raman scattering places mode strengths of corner-sharing Ge(S1/2)4 tetrahedra (A), ethane-like Ge2(S1/2)6 units (B), and the distorted rocksalt Ge(S1/6)6 units (C) at approximately 93.4:3.6:3.0 not normalized for mode cross-sections. Mössbauer spectroscopy places the concentration of these units as A : B : C = 76.2:8.8 :15. The drastic reduction in the slope of the glass transition temperature T g with Ge content x coincides with first appearance of these units once x exceeds 32.50, suggesting that these units are demixed and form separate nanophases to lower the global connectivity of the glass network.","PeriodicalId":20016,"journal":{"name":"Philosophical Magazine Part B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80040987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-10-01DOI: 10.1080/13642810208220734
P. Münster, M. Sarret, T. Mohammed‐Brahim, N. Coulon, J. Mevellec
Abstract Amorphous silicon films have been deposited on glass by subatmosphericpressure chemical vapour deposition and then crystallized by solid-phase crystallization. The structural and electrical properties of these polycrystalline silicon films are presented in this work. Good crystalline quality at a deposition pressure of about 400 mbar has been achieved as well as values of the mobilitylifetime product above 10−5cm2V−1 and an ambipolar diffusion length near 200 nm. Depending upon the deposition temperature and pressure, growth rates of up to 20 μm h−1 can be obtained. In-situ doping with arsenic and boron has been studied using Hall effect measurements. High mobilities around 45cm2V−1s−1 have been attained for highly n-type doped samples and mobilities in the range from 20 to 30 cm2 V−1 s−1 for boron-doped samples.
{"title":"Polycrystalline silicon deposited on glass by subatmospheric-pressure chemical vapour deposition at a high rate","authors":"P. Münster, M. Sarret, T. Mohammed‐Brahim, N. Coulon, J. Mevellec","doi":"10.1080/13642810208220734","DOIUrl":"https://doi.org/10.1080/13642810208220734","url":null,"abstract":"Abstract Amorphous silicon films have been deposited on glass by subatmosphericpressure chemical vapour deposition and then crystallized by solid-phase crystallization. The structural and electrical properties of these polycrystalline silicon films are presented in this work. Good crystalline quality at a deposition pressure of about 400 mbar has been achieved as well as values of the mobilitylifetime product above 10−5cm2V−1 and an ambipolar diffusion length near 200 nm. Depending upon the deposition temperature and pressure, growth rates of up to 20 μm h−1 can be obtained. In-situ doping with arsenic and boron has been studied using Hall effect measurements. High mobilities around 45cm2V−1s−1 have been attained for highly n-type doped samples and mobilities in the range from 20 to 30 cm2 V−1 s−1 for boron-doped samples.","PeriodicalId":20016,"journal":{"name":"Philosophical Magazine Part B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77875794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-10-01DOI: 10.1080/13642810208220732
I. D. Desnica-Frankovi
Abstract Implantation-induced microstructural modifications have been measured in amorphous GaAs using Raman scattering spectroscopy and optical absorption in the subgap region. Additional evidence is given that the amorphous phase consists of two components which continuously evolve as a function of ion dose. A characteristic disorder-related Urbach parameter from the absorption measurements was used as a measure of the total disorder at each dose, whereas Raman results enabled the separation of a random component (amorphous continuous random network (a-CRN)) and a medium-rangeordered component (amorphous boson peak (a-Br)) of the amorphous network. As the dose is increased, the a-CRN fraction gradually converts into the a-BP fraction. The decrease in the remaining a-CRN fraction with increasing dose correlates with the decrease in the disorder as observed by absorption measurements and the Urbach parameter.
{"title":"Exponential absorption edge and implantation-induced modifications in amorphous gallium arsenide","authors":"I. D. Desnica-Frankovi","doi":"10.1080/13642810208220732","DOIUrl":"https://doi.org/10.1080/13642810208220732","url":null,"abstract":"Abstract Implantation-induced microstructural modifications have been measured in amorphous GaAs using Raman scattering spectroscopy and optical absorption in the subgap region. Additional evidence is given that the amorphous phase consists of two components which continuously evolve as a function of ion dose. A characteristic disorder-related Urbach parameter from the absorption measurements was used as a measure of the total disorder at each dose, whereas Raman results enabled the separation of a random component (amorphous continuous random network (a-CRN)) and a medium-rangeordered component (amorphous boson peak (a-Br)) of the amorphous network. As the dose is increased, the a-CRN fraction gradually converts into the a-BP fraction. The decrease in the remaining a-CRN fraction with increasing dose correlates with the decrease in the disorder as observed by absorption measurements and the Urbach parameter.","PeriodicalId":20016,"journal":{"name":"Philosophical Magazine Part B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90928557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-09-01DOI: 10.1080/13642810208220726
H. Sato, H. Iba, T. Naganuma, Y. Kagawa
Abstract Glass particles with a size d p of 38–53 μm are incorporated into a clear epoxy matrix and the light transmittance T L of the composites is measured in the wavelength γ range from 200 to 1100 nm. The net difference ▵n c between the refractive indices of the glass particles and the matrix of the fabricated composite ranged from nearly zero to 0.03. This difference between the refractive indices is achieved by, firstly, selecting the optical properties of dispersed glass particles and secondly, changing the thermal stress in the composite. The effect of the difference ▵n c between the refractive indices of the glass particles and the epoxy matrix on the light transmittance of the composite is obtained. It is found that the light transmission spectrum of the composite is correlated with the relationship between the wavelength dispersion curves of the refractive indices of the glass particles and the matrix. At a fixed wavelength, the T L−▵n c curve is only dependent on the particle size and volume fraction. The measured T L−▵n c curves of the composite at a given particle volume fraction and a given particle size show that the maximum light transmittance of the composite appears when ▵n c ≈ 0. The value is about 92% and is nearly the same as that of the pure epoxy matrix.
{"title":"Effects of the difference between the refractive indices of constituent materials on the light transmittance of glass-particle-dispersed epoxy-matrix optical composites","authors":"H. Sato, H. Iba, T. Naganuma, Y. Kagawa","doi":"10.1080/13642810208220726","DOIUrl":"https://doi.org/10.1080/13642810208220726","url":null,"abstract":"Abstract Glass particles with a size d p of 38–53 μm are incorporated into a clear epoxy matrix and the light transmittance T L of the composites is measured in the wavelength γ range from 200 to 1100 nm. The net difference ▵n c between the refractive indices of the glass particles and the matrix of the fabricated composite ranged from nearly zero to 0.03. This difference between the refractive indices is achieved by, firstly, selecting the optical properties of dispersed glass particles and secondly, changing the thermal stress in the composite. The effect of the difference ▵n c between the refractive indices of the glass particles and the epoxy matrix on the light transmittance of the composite is obtained. It is found that the light transmission spectrum of the composite is correlated with the relationship between the wavelength dispersion curves of the refractive indices of the glass particles and the matrix. At a fixed wavelength, the T L−▵n c curve is only dependent on the particle size and volume fraction. The measured T L−▵n c curves of the composite at a given particle volume fraction and a given particle size show that the maximum light transmittance of the composite appears when ▵n c ≈ 0. The value is about 92% and is nearly the same as that of the pure epoxy matrix.","PeriodicalId":20016,"journal":{"name":"Philosophical Magazine Part B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82595575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-09-01DOI: 10.1080/13642810208220728
Z. X. Zhou, G. Cao, S. McCall, J. Crow, R. P. Guertin, C. Mielke, D. Rickel
Abstract The rare-earth ruthenate Pr3RuO7 is a Mott insulator displaying magnetic ordering at two temperatures T N1 = 36 K and T N2 = 55 K. By substituting diamagnetic La for Pr and diamagnetic Nb for Ru, T N1 is shown to be associated with ordering among the rare earths and T N2 among the Ru cations. These results are similar to those of Sm3RuO7, but the ordering temperatures for Pr3RuC7 are large compared with all other known Ln3MO7 systems and there is less divergence between field-cooled and zero-field-cooled magnetic susceptibility for T < T N2. Isothermal magnetization measurements, including pulsed-field measurements, show hysteretic-field-induced transitions at B ≈ 4T for T ≪ TN1 associated with a spin reorientation of the Pr moments. Further characterization of Pr3RuO7 is provided from measurements of the heat capacity for 2K < T < 17 K and electrical resistivity for 100K < T < 300 K.
摘要钌酸稀土Pr3RuO7是一种Mott绝缘体，在tn1 = 36 K和tn2 = 55 K两种温度下显示出磁性有序。用抗磁性的La代替Pr，用抗磁性的Nb代替Ru，结果表明tn1与稀土元素间的有序性有关，而tn2与稀土元素间的有序性有关。这些结果与Sm3RuO7相似，但Pr3RuC7的有序温度比所有其他已知的Ln3MO7体系都大，并且在T < T N2时，场冷磁化率和零场冷磁化率之间的差异较小。等温磁化测量，包括脉冲场测量，显示出在T≪TN1时，在B≈4T处的迟滞场诱导跃变与Pr矩的自旋重定向有关。Pr3RuO7在2K < T < 17 K时的热容量和100K < T < 300 K时的电阻率可以进一步表征。
{"title":"Magnetic interactions in (Pr, La)3RuO7 and Pr3(Ru, Nb)O7","authors":"Z. X. Zhou, G. Cao, S. McCall, J. Crow, R. P. Guertin, C. Mielke, D. Rickel","doi":"10.1080/13642810208220728","DOIUrl":"https://doi.org/10.1080/13642810208220728","url":null,"abstract":"Abstract The rare-earth ruthenate Pr3RuO7 is a Mott insulator displaying magnetic ordering at two temperatures T N1 = 36 K and T N2 = 55 K. By substituting diamagnetic La for Pr and diamagnetic Nb for Ru, T N1 is shown to be associated with ordering among the rare earths and T N2 among the Ru cations. These results are similar to those of Sm3RuO7, but the ordering temperatures for Pr3RuC7 are large compared with all other known Ln3MO7 systems and there is less divergence between field-cooled and zero-field-cooled magnetic susceptibility for T < T N2. Isothermal magnetization measurements, including pulsed-field measurements, show hysteretic-field-induced transitions at B ≈ 4T for T ≪ TN1 associated with a spin reorientation of the Pr moments. Further characterization of Pr3RuO7 is provided from measurements of the heat capacity for 2K < T < 17 K and electrical resistivity for 100K < T < 300 K.","PeriodicalId":20016,"journal":{"name":"Philosophical Magazine Part B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73211590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-09-01DOI: 10.1080/13642810208220727
K. Matsumura, Yutaka Kagawa
Abstract The phase profile of a transmitted laser beam through glass-particle-dispersed epoxy-matrix composites was measured using the interferometric measurement method. The effect of dispersed particles on the light scattering behaviour of the composite was determined from the difference between the in-line and total light transmittance. The difference between the light transmittances increases with increase in the particle volume fraction and this result indicates that the glass particles are a major source of light scattering in the composite. The phase profile changes with the addition of glass particles; a higher particle volume fraction yields a larger phase profile distribution. This result demonstrates that the phase profile of the transmitted light is strongly correlated with the total amount of light scattering source in the composite. The measured phase delay becomes pronounced on increasing separation from the laser beam axis and this behaviour is explained by increase in the laser beam path in the composite caused by the light scattering.
{"title":"Phase profiles of transmitted light through glass-particle-dispersed epoxy-matrix composites","authors":"K. Matsumura, Yutaka Kagawa","doi":"10.1080/13642810208220727","DOIUrl":"https://doi.org/10.1080/13642810208220727","url":null,"abstract":"Abstract The phase profile of a transmitted laser beam through glass-particle-dispersed epoxy-matrix composites was measured using the interferometric measurement method. The effect of dispersed particles on the light scattering behaviour of the composite was determined from the difference between the in-line and total light transmittance. The difference between the light transmittances increases with increase in the particle volume fraction and this result indicates that the glass particles are a major source of light scattering in the composite. The phase profile changes with the addition of glass particles; a higher particle volume fraction yields a larger phase profile distribution. This result demonstrates that the phase profile of the transmitted light is strongly correlated with the total amount of light scattering source in the composite. The measured phase delay becomes pronounced on increasing separation from the laser beam axis and this behaviour is explained by increase in the laser beam path in the composite caused by the light scattering.","PeriodicalId":20016,"journal":{"name":"Philosophical Magazine Part B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86161244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-08-01DOI: 10.1080/13642810208218365
D. Chen, L. Pascual
Abstract The circular susceptibility of axially magnetized, nearly non-magnetostrictive Co–Fe–Si–B amorphous wires can have qualitatively different behaviour from and be up to 55 times greater than what is expected by standard domain magnetization rotations theory. This may be caused by intrinsic and annealing-induced soft and hard magnetic inclusions embedded in the soft magnetic matrix; when the spontaneous magnetization of the inclusions is greater than that of the matrix pointing in the same axial direction, exchange-coupled disc-like soft magnetic structures form and they may hugely enhance the circular magnetization. Our results provide a sensitive tool to probe the structures in amorphous wires and suggest an important factor to consider in the study of giant magneto-impedance.
{"title":"Magnetic-inclusion-enhanced circular susceptibility in axially magnetized Co–Fe–Si–B amorphous wires","authors":"D. Chen, L. Pascual","doi":"10.1080/13642810208218365","DOIUrl":"https://doi.org/10.1080/13642810208218365","url":null,"abstract":"Abstract The circular susceptibility of axially magnetized, nearly non-magnetostrictive Co–Fe–Si–B amorphous wires can have qualitatively different behaviour from and be up to 55 times greater than what is expected by standard domain magnetization rotations theory. This may be caused by intrinsic and annealing-induced soft and hard magnetic inclusions embedded in the soft magnetic matrix; when the spontaneous magnetization of the inclusions is greater than that of the matrix pointing in the same axial direction, exchange-coupled disc-like soft magnetic structures form and they may hugely enhance the circular magnetization. Our results provide a sensitive tool to probe the structures in amorphous wires and suggest an important factor to consider in the study of giant magneto-impedance.","PeriodicalId":20016,"journal":{"name":"Philosophical Magazine Part B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85481804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-08-01DOI: 10.1080/13642810208218366
F. Abdel-Wahab
Abstract A new analysis of electronic transport in chalcogenide glasses, based on bipolaron hopping in the extended pair approximation, is presented. It is assumed that the relaxation time of the carrier when hopping has a Meyer-Neldel type of temperature dependence instead of a simple activated form. In this way, the experimental data for both dc conductivity and ac conductivity can be fitted over a wide range of temperatures, and for a number of glasses using the same set of parameters.
{"title":"Unified hopping model for dc and ac conduction in chalcogenide glasses","authors":"F. Abdel-Wahab","doi":"10.1080/13642810208218366","DOIUrl":"https://doi.org/10.1080/13642810208218366","url":null,"abstract":"Abstract A new analysis of electronic transport in chalcogenide glasses, based on bipolaron hopping in the extended pair approximation, is presented. It is assumed that the relaxation time of the carrier when hopping has a Meyer-Neldel type of temperature dependence instead of a simple activated form. In this way, the experimental data for both dc conductivity and ac conductivity can be fitted over a wide range of temperatures, and for a number of glasses using the same set of parameters.","PeriodicalId":20016,"journal":{"name":"Philosophical Magazine Part B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78268166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2002-08-01DOI: 10.1080/13642810208218364
U. Pustogowa
Abstract Using the results of relativistic multiple-scattering theory the origin of spin polarization in core-core-valence (CCV) Auger electron spectroscopy (AES) is discussed. The contributions of core states and the valence band are analysed for the surface layer of bcc Fe(100) as calculated by means of the fully relativistic spin-polarized screened Korringa–Kohn–Rostoker method for layered systems. All possible core-state combinations (different CCV Auger electron spectra) are compared, showing characteristic differences independent of the underlying valence-band density of states.
{"title":"Spin-polarized Auger electron spectroscopy","authors":"U. Pustogowa","doi":"10.1080/13642810208218364","DOIUrl":"https://doi.org/10.1080/13642810208218364","url":null,"abstract":"Abstract Using the results of relativistic multiple-scattering theory the origin of spin polarization in core-core-valence (CCV) Auger electron spectroscopy (AES) is discussed. The contributions of core states and the valence band are analysed for the surface layer of bcc Fe(100) as calculated by means of the fully relativistic spin-polarized screened Korringa–Kohn–Rostoker method for layered systems. All possible core-state combinations (different CCV Auger electron spectra) are compared, showing characteristic differences independent of the underlying valence-band density of states.","PeriodicalId":20016,"journal":{"name":"Philosophical Magazine Part B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78127395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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