In this study, fatigue crack propagation tests were performed to obtain fatigue fracture surfaces on compact tension type specimens of A5052 aluminum alloy and S25C carbon steel. The fatigue fracture surfaces were observed using a scanning laser microscope system. Based on the digital data thus obtained, an imaginary fracture surface was reconstructed in a three-dimensional (3D) space using a personal computer. Fractal analysis proposed by Mandelbrot was applied to such 3D surfaces and a hyperbola model was accepted to represent the Richardson effect. Because of the Richardson effect thus analyzed, fractal features were distinguished in the fracture surface irregularity. Results demonstrated that the geometrical irregularity of the surface was well evaluated by combining the fractal dimension and additional indices termed as "indices of fracture surface nature", and that the fractal dimension and the additional indices were associated with the stress intensity factor range of AK.
{"title":"Fractal and fracture mechanics analyses of fatigue fracture surfaces of metallic materials","authors":"T. Sakai","doi":"10.1299/KIKAIA.66.2183","DOIUrl":"https://doi.org/10.1299/KIKAIA.66.2183","url":null,"abstract":"In this study, fatigue crack propagation tests were performed to obtain fatigue fracture surfaces on compact tension type specimens of A5052 aluminum alloy and S25C carbon steel. The fatigue fracture surfaces were observed using a scanning laser microscope system. Based on the digital data thus obtained, an imaginary fracture surface was reconstructed in a three-dimensional (3D) space using a personal computer. Fractal analysis proposed by Mandelbrot was applied to such 3D surfaces and a hyperbola model was accepted to represent the Richardson effect. Because of the Richardson effect thus analyzed, fractal features were distinguished in the fracture surface irregularity. Results demonstrated that the geometrical irregularity of the surface was well evaluated by combining the fractal dimension and additional indices termed as \"indices of fracture surface nature\", and that the fractal dimension and the additional indices were associated with the stress intensity factor range of AK.","PeriodicalId":16679,"journal":{"name":"Journal of Optoelectronics and Advanced Materials","volume":"9 1","pages":"2504-2508"},"PeriodicalIF":0.5,"publicationDate":"2013-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1299/KIKAIA.66.2183","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66360893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Constantin, Stasi Iuliana-Valentina, Lalau Cornel-Constantin
The addition of alumina and zirconia nanoparticles into nickel plating bath induces changes in the surface morphology and in the preferred crystallographic orientation of the nanocomposite thin layers electrodeposited on cooper substrates. The typical morphology for nickel deposits is pyramidal, but the addition of alumina particles in concentrations between 5 g/l and 10 g/l changes this morphology to hemispherical. The behavior of prepared Ni/Al 2 O 3 and Ni/ZrO 2 nanocomposite thin layers during corroding process in various solutions was investigated by using polarization curve, impedance spectroscopy, and Mott-Schottky techniques. The experimental results indicate the beneficial roles of alumina and zirconia nanoparticles on nanocomposite materials.
{"title":"Corrosion Behavior of Ni/Al2O3 and Ni/ZrO2 Nanocomposite Thin Films","authors":"G. Constantin, Stasi Iuliana-Valentina, Lalau Cornel-Constantin","doi":"10.5772/13844","DOIUrl":"https://doi.org/10.5772/13844","url":null,"abstract":"The addition of alumina and zirconia nanoparticles into nickel plating bath induces changes in the surface morphology and in the preferred crystallographic orientation of the nanocomposite thin layers electrodeposited on cooper substrates. The typical morphology for nickel deposits is pyramidal, but the addition of alumina particles in concentrations between 5 g/l and 10 g/l changes this morphology to hemispherical. The behavior of prepared Ni/Al 2 O 3 and Ni/ZrO 2 nanocomposite thin layers during corroding process in various solutions was investigated by using polarization curve, impedance spectroscopy, and Mott-Schottky techniques. The experimental results indicate the beneficial roles of alumina and zirconia nanoparticles on nanocomposite materials.","PeriodicalId":16679,"journal":{"name":"Journal of Optoelectronics and Advanced Materials","volume":"11 1","pages":"146-154"},"PeriodicalIF":0.5,"publicationDate":"2011-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.5772/13844","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70919539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-01-10DOI: 10.1142/S0217984910022172
S. C. Baidoc, I. Ardelean
Structural analysis of xAg20(100-x)[3B 2 O 3 ·As 2 O 3 ] glass system, with 0 ≤ x ≤ 10 mol%, was performed by means of FT - IR and Raman spectroscopies. The purpose of this work is to investigate the structural changes that appear in the 3B 2 O3·As 2 O 3 glass matrix with the addition and increasing of silver ions content. Boroxol rings, pyro-, ortho-, di-, tri-, tetraand penta-borate groups and structural units characteristic to As 2 O 3 were found in the structure of the studied glasses. At small silver oxide content the predominant structural units are those in which boron is three-fold coordinated. For higher silver oxide concentrations (x ≥ 5 mol%) the number of four-fold coordinated boron units is increasing. The changes in the A r = A 4 /A 3 (A 4 and A 3 reflect the relative amount of tetrahedral (BO 4 and B∅ - 4 ) and triangular (BO 3 and BO 2 O - ) borate species) ratio also shows the fact that silver oxide influence the boron coordination number. The Raman analysis leads to similar conclusions as FT- IR measurements.
用红外光谱和拉曼光谱对0≤x≤10 mol%的xAg20(100-x)[3B 2o3·As 2o3]玻璃体系进行了结构分析。本研究的目的是研究随着银离子的添加和增加，3B o2·As o2玻璃基体的结构变化。硼砂环、热硼酸、邻硼酸、二硼酸、三硼酸、四硼酸和五硼酸基团以及具有as2o3特征的结构单元均存在于所研究的玻璃结构中。在氧化银含量小的情况下，主要的结构单元是那些硼是三重配位的结构单元。当氧化银浓度较高(x≥5 mol%)时，四重配位硼单元的数量增加。A r = A 4 /A 3 (A 4和A 3反映了四面体(bo4和B∅- 4)和三角形(bo3和bo2o -)硼酸盐种类的相对数量)比的变化也表明氧化银影响硼配位数的事实。拉曼分析得出了与FT- IR测量相似的结论。
{"title":"FT -IR and Raman spectroscopic studies of xAg2O-(100-x)[3B2O3·As2O3] glass system","authors":"S. C. Baidoc, I. Ardelean","doi":"10.1142/S0217984910022172","DOIUrl":"https://doi.org/10.1142/S0217984910022172","url":null,"abstract":"Structural analysis of xAg20(100-x)[3B 2 O 3 ·As 2 O 3 ] glass system, with 0 ≤ x ≤ 10 mol%, was performed by means of FT - IR and Raman spectroscopies. The purpose of this work is to investigate the structural changes that appear in the 3B 2 O3·As 2 O 3 glass matrix with the addition and increasing of silver ions content. Boroxol rings, pyro-, ortho-, di-, tri-, tetraand penta-borate groups and structural units characteristic to As 2 O 3 were found in the structure of the studied glasses. At small silver oxide content the predominant structural units are those in which boron is three-fold coordinated. For higher silver oxide concentrations (x ≥ 5 mol%) the number of four-fold coordinated boron units is increasing. The changes in the A r = A 4 /A 3 (A 4 and A 3 reflect the relative amount of tetrahedral (BO 4 and B∅ - 4 ) and triangular (BO 3 and BO 2 O - ) borate species) ratio also shows the fact that silver oxide influence the boron coordination number. The Raman analysis leads to similar conclusions as FT- IR measurements.","PeriodicalId":16679,"journal":{"name":"Journal of Optoelectronics and Advanced Materials","volume":"10 1","pages":"3205-3208"},"PeriodicalIF":0.5,"publicationDate":"2010-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/S0217984910022172","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"63863841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hongbo Yu, M. Ozturk, P. Demirel, H. Çakmak, T. Buyuklimanli, W. Ou, E. Ozbay
We report growth optimizations of the thin AIN film on (0001) 4H-SiC substrates by metalorganic chemical vapor deposition. The influence of growth conditions, such as growth temperature and the V/III molar ratio, on the material quality of AIN film is studied. The surface morphology and crystalline quality of the epitaxial layers are investigated by atomic force microscope, X-ray diffraction, and transmission electronic microscope. A new approach is demonstrated to improve the crystalline quality of a 100 nm-thick AIN film by the use of a 5 nm-thick low temperature AIN nucleation layer. Compared to a conventional AIN layer directly grown on SiC substrate at high temperature, the surface morphology of two-step AIN film is remarkably improved along with a decreasing of defect density, leading to the improvement of crystalline quality for the subsequently grown GaN layer. The mechanisms of crystalline quality improvement by use of a low temperature AIN nucleation layer are also investigated and discussed.
{"title":"Experimental study of two-step growth of thin AlN film on 4H-SiC substrate by Metalorganic Chemical Vapor Deposition","authors":"Hongbo Yu, M. Ozturk, P. Demirel, H. Çakmak, T. Buyuklimanli, W. Ou, E. Ozbay","doi":"10.5072/ZENODO.38088","DOIUrl":"https://doi.org/10.5072/ZENODO.38088","url":null,"abstract":"We report growth optimizations of the thin AIN film on (0001) 4H-SiC substrates by metalorganic chemical vapor deposition. The influence of growth conditions, such as growth temperature and the V/III molar ratio, on the material quality of AIN film is studied. The surface morphology and crystalline quality of the epitaxial layers are investigated by atomic force microscope, X-ray diffraction, and transmission electronic microscope. A new approach is demonstrated to improve the crystalline quality of a 100 nm-thick AIN film by the use of a 5 nm-thick low temperature AIN nucleation layer. Compared to a conventional AIN layer directly grown on SiC substrate at high temperature, the surface morphology of two-step AIN film is remarkably improved along with a decreasing of defect density, leading to the improvement of crystalline quality for the subsequently grown GaN layer. The mechanisms of crystalline quality improvement by use of a low temperature AIN nucleation layer are also investigated and discussed.","PeriodicalId":16679,"journal":{"name":"Journal of Optoelectronics and Advanced Materials","volume":"12 1","pages":"2406-2412"},"PeriodicalIF":0.5,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70792405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Ates, M. Saglam, B. Güzeldir, M. Yıldırım, Aykut Astam
Cu/CuS/p-Si/Al structure formed using CuS thin film on p-Si substrate. CuS thin film has been grown with using Successive Ionic Layer Adsorption and Reaction (SILAR) method. The Cu/CuS/p-Si/Al structure has demonstrated clearly rectifying behavior by the current-voltage (I-V) curves studied at room temperature. The characteristic parameters such as barrier height, ideality factor and series resistance of Cu/CuS/p-Si/Al structure have been calculated from the forward bias I-V and reverse bias C -2 -V characteristics. The ideality factor and barrier height have been obtained as n=1.63 and Φ b =0.69 eV by applying a thermo-ionic emission theory. At high current densities in the forward direction, the series resistance effect has been observed. The values of R s obtained from dV/d(InI) - / and H(I) - / plots are near to each others (R s =340.33 □ and R s =346.24 □, respectively). In the same way, the barrier height calculated from C -2 -V characteristics have been varied from 0.523 to 0.601 eV. Furthermore, the density distribution of interface states of the multilayer device has been obtained from the semi-log forward bias I-V characteristics. It has been seen that the N ss has almost an exponential rise with bias voltage from top of the valance band toward to mid gap.
{"title":"The electrical characteristics of Cu/CuS/p-Si/Al structure","authors":"A. Ates, M. Saglam, B. Güzeldir, M. Yıldırım, Aykut Astam","doi":"10.5072/ZENODO.34426","DOIUrl":"https://doi.org/10.5072/ZENODO.34426","url":null,"abstract":"Cu/CuS/p-Si/Al structure formed using CuS thin film on p-Si substrate. CuS thin film has been grown with using Successive Ionic Layer Adsorption and Reaction (SILAR) method. The Cu/CuS/p-Si/Al structure has demonstrated clearly rectifying behavior by the current-voltage (I-V) curves studied at room temperature. The characteristic parameters such as barrier height, ideality factor and series resistance of Cu/CuS/p-Si/Al structure have been calculated from the forward bias I-V and reverse bias C -2 -V characteristics. The ideality factor and barrier height have been obtained as n=1.63 and Φ b =0.69 eV by applying a thermo-ionic emission theory. At high current densities in the forward direction, the series resistance effect has been observed. The values of R s obtained from dV/d(InI) - / and H(I) - / plots are near to each others (R s =340.33 □ and R s =346.24 □, respectively). In the same way, the barrier height calculated from C -2 -V characteristics have been varied from 0.523 to 0.601 eV. Furthermore, the density distribution of interface states of the multilayer device has been obtained from the semi-log forward bias I-V characteristics. It has been seen that the N ss has almost an exponential rise with bias voltage from top of the valance band toward to mid gap.","PeriodicalId":16679,"journal":{"name":"Journal of Optoelectronics and Advanced Materials","volume":"12 1","pages":"1466-1471"},"PeriodicalIF":0.5,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70790866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Keziban Can, Mustafa Ozmen, L. Gurfidan, I. H. Gubbuk, E. Kaymak, M. Ersoz, Z. Ozbek, R. Çapan
In the present work the monolayer properties at the air-water interface of Octyltriethoxysilane (C 8 TES) molecules are investigated using Langmuir isotherm graphs. Uniform and high quality Langmuir-Blodgett films of these molecules are prepared and characterized by UV-visible, atomic force microscopy and quartz crystal microbalance measurements to determine the deposition quality of these films. High transfer ratio of about 0.99 at a deposition pressure of 11 mN/m was obtained. The contact angle of water was 93.17° with a surface free energy of 23.8 mN/m. The use of soluble triethoxybased silane coupling agents under anhydrous conditions is shown to produce surfaces with a minimal number of surface defects. C 8 TES material has been demonstrated to produce well organised LB films and is shown to be a good candidate for application in the field of biosensors.
{"title":"Fabrication of octyltriethoxysilane Langmuir-Blodgett thin film","authors":"Keziban Can, Mustafa Ozmen, L. Gurfidan, I. H. Gubbuk, E. Kaymak, M. Ersoz, Z. Ozbek, R. Çapan","doi":"10.5072/ZENODO.33162","DOIUrl":"https://doi.org/10.5072/ZENODO.33162","url":null,"abstract":"In the present work the monolayer properties at the air-water interface of Octyltriethoxysilane (C 8 TES) molecules are investigated using Langmuir isotherm graphs. Uniform and high quality Langmuir-Blodgett films of these molecules are prepared and characterized by UV-visible, atomic force microscopy and quartz crystal microbalance measurements to determine the deposition quality of these films. High transfer ratio of about 0.99 at a deposition pressure of 11 mN/m was obtained. The contact angle of water was 93.17° with a surface free energy of 23.8 mN/m. The use of soluble triethoxybased silane coupling agents under anhydrous conditions is shown to produce surfaces with a minimal number of surface defects. C 8 TES material has been demonstrated to produce well organised LB films and is shown to be a good candidate for application in the field of biosensors.","PeriodicalId":16679,"journal":{"name":"Journal of Optoelectronics and Advanced Materials","volume":"12 1","pages":"1552-1555"},"PeriodicalIF":0.5,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70790817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-01-01DOI: 10.1016/B978-0-12-388429-9.00005-4
V. Mikla
{"title":"Xerographic spectroscopy of gap states: Se-rich amorphous semiconductors","authors":"V. Mikla","doi":"10.1016/B978-0-12-388429-9.00005-4","DOIUrl":"https://doi.org/10.1016/B978-0-12-388429-9.00005-4","url":null,"abstract":"","PeriodicalId":16679,"journal":{"name":"Journal of Optoelectronics and Advanced Materials","volume":"12 1","pages":"1621-1635"},"PeriodicalIF":0.5,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"54077426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Yovcheva, I. Naydenova, I. Vlaeva, S. Martin, V. Toal, S. Sainov
The present work studies the optical and holographic characteristics of acrylamide-based photopolymer layers. The refractive index change of a liquid acrylamide photopolymer due to exposure at 532 nm is obtained for the first time, using a critical angle laser micro-refractometer. The 30 μm thick solid photopolymer films are prepared by casting on glass substrates. Bragg holographic gratings with spatial frequencies of 710 mm -1 , 1050 mm -1 and 1600 mm -1 are recorded using a diode laser operating at 532 nm wavelength. We investigate the dependence of the diffraction efficiency on the exposure energy. The obtained results are compared with the Stetson holographic recording method, where two gratings are simultaneously recorded in the same location with spatial frequencies of 2020 mm -1 and 3670 mm -1 , using a totally reflected reference wave from the air-photopolymer interface. Despite the fact that in the latter method the two gratings share the same dynamic range, higher diffraction efficiencies are observed.
本文研究了丙烯酰胺基光聚合物层的光学和全息特性。利用临界角度激光微折射仪，首次获得了液体丙烯酰胺光聚合物在532 nm处曝光后的折射率变化。在玻璃基板上采用浇铸法制备了30 μm厚的固体光聚合物薄膜。利用波长为532 nm的二极管激光器记录了空间频率为710 mm -1、1050 mm -1和1600 mm -1的Bragg全息光栅。我们研究了衍射效率与曝光能量的关系。利用来自空气-光聚合物界面的全反射参考波，在同一位置同时记录两个光栅，空间频率分别为2020 mm -1和3670 mm -1，并将所得结果与Stetson全息记录方法进行了比较。尽管在后一种方法中，两个光栅具有相同的动态范围，但观察到更高的衍射效率。
{"title":"Optical and Holographic Characteristics of Photopolymer Layers","authors":"T. Yovcheva, I. Naydenova, I. Vlaeva, S. Martin, V. Toal, S. Sainov","doi":"10.21427/D7XW42","DOIUrl":"https://doi.org/10.21427/D7XW42","url":null,"abstract":"The present work studies the optical and holographic characteristics of acrylamide-based photopolymer layers. The refractive index change of a liquid acrylamide photopolymer due to exposure at 532 nm is obtained for the first time, using a critical angle laser micro-refractometer. The 30 μm thick solid photopolymer films are prepared by casting on glass substrates. Bragg holographic gratings with spatial frequencies of 710 mm -1 , 1050 mm -1 and 1600 mm -1 are recorded using a diode laser operating at 532 nm wavelength. We investigate the dependence of the diffraction efficiency on the exposure energy. The obtained results are compared with the Stetson holographic recording method, where two gratings are simultaneously recorded in the same location with spatial frequencies of 2020 mm -1 and 3670 mm -1 , using a totally reflected reference wave from the air-photopolymer interface. Despite the fact that in the latter method the two gratings share the same dynamic range, higher diffraction efficiencies are observed.","PeriodicalId":16679,"journal":{"name":"Journal of Optoelectronics and Advanced Materials","volume":"11 1","pages":"1452-1455"},"PeriodicalIF":0.5,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67752199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-01-01DOI: 10.1088/1742-6596/100/8/082026
I Mustata, A Anghel, C P Lungu, O Pompilian, V Kuncser, G Schinteie
: Co-MgO granular films presenting TMR effects were prepared by thermo-ionic vacuum arc (TVA) method with the simultaneous ignition of plasma in Co and MgO vapors, respectively. The processing method is suitable for the simultaneous preparation of films of different relative content of Co in the MgO insulating matrix. Morphologic, structural and magnetic behaviors were analyzed in as prepared and annealed samples. The influence of the Co content on the magnetic properties of the prepared films was analyzed, in correlation with tunneling magneto-resistance effects. The tunneling magneto-resistance effect is maximal for certain Co content. This behavior was interpreted by the contrary effects of decreasing the average size of the magnetic grains, and hence the average inter-grains distance at higher Co relative content, and the enhanced magnetic disorder in very fine grains dispersed in the insulating matrix. This mechanism was suggested by the comportment of as prepared and thermally annealed samples.
{"title":"Tunneling magneto-resistance granular thin films deposited by thermo-ionic vacuum arc technique","authors":"I Mustata, A Anghel, C P Lungu, O Pompilian, V Kuncser, G Schinteie","doi":"10.1088/1742-6596/100/8/082026","DOIUrl":"https://doi.org/10.1088/1742-6596/100/8/082026","url":null,"abstract":": Co-MgO granular films presenting TMR effects were prepared by thermo-ionic vacuum arc (TVA) method with the simultaneous ignition of plasma in Co and MgO vapors, respectively. The processing method is suitable for the simultaneous preparation of films of different relative content of Co in the MgO insulating matrix. Morphologic, structural and magnetic behaviors were analyzed in as prepared and annealed samples. The influence of the Co content on the magnetic properties of the prepared films was analyzed, in correlation with tunneling magneto-resistance effects. The tunneling magneto-resistance effect is maximal for certain Co content. This behavior was interpreted by the contrary effects of decreasing the average size of the magnetic grains, and hence the average inter-grains distance at higher Co relative content, and the enhanced magnetic disorder in very fine grains dispersed in the insulating matrix. This mechanism was suggested by the comportment of as prepared and thermally annealed samples.","PeriodicalId":16679,"journal":{"name":"Journal of Optoelectronics and Advanced Materials","volume":"100 1","pages":"082026"},"PeriodicalIF":0.5,"publicationDate":"2008-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/1742-6596/100/8/082026","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60590465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-09-01DOI: 10.1142/9789812770165_0037
Y. Chen
In this paper, PSPICE is implemented to model and simulate the characteristic of thin film bulk acoustic resonator (FBAR). Both analogy equivalent circuits of Acoustic transmission line and Mason model is proposed and transferred to the PSPICE model by using the controlled-source method. The physical parameters such as piezoelectric materials and its thickness, electrode material, area and its thickness affecting the properties of the FBAS are discussed. Finally, we have implemented the FBAR to design a ladder type filter with a center frequency at 1.1 GHz and bandwidth about 60.9%. The study results in that PSPICE is an effective tool for the FBAR modeling and ladder type filter design.
{"title":"Modeling of thin film bulk acoustic wave resonators and ladder-type filter design","authors":"Y. Chen","doi":"10.1142/9789812770165_0037","DOIUrl":"https://doi.org/10.1142/9789812770165_0037","url":null,"abstract":"In this paper, PSPICE is implemented to model and simulate the characteristic of thin film bulk acoustic resonator (FBAR). Both analogy equivalent circuits of Acoustic transmission line and Mason model is proposed and transferred to the PSPICE model by using the controlled-source method. The physical parameters such as piezoelectric materials and its thickness, electrode material, area and its thickness affecting the properties of the FBAS are discussed. Finally, we have implemented the FBAR to design a ladder type filter with a center frequency at 1.1 GHz and bandwidth about 60.9%. The study results in that PSPICE is an effective tool for the FBAR modeling and ladder type filter design.","PeriodicalId":16679,"journal":{"name":"Journal of Optoelectronics and Advanced Materials","volume":"12 1","pages":"1993-1999"},"PeriodicalIF":0.5,"publicationDate":"2007-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1142/9789812770165_0037","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64023277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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