The crystal structure of CaSrFe<sub>0.75</sub>Co<sub>0.75</sub>Mn<sub>0.5</sub>O<sub>6−δ</sub> is investigated through neutron diffraction techniques in this study. The...The crystal structure of CaSrFe<sub>0.75</sub>Co<sub>0.75</sub>Mn<sub>0.5</sub>O<sub>6−δ</sub> is investigated through neutron diffraction techniques in this study. The material is synthesized using a solid-state synthesis method at a temperature of 1200˚C. Neutron diffraction data is subjected to Rietveld refinement, and a comparative analysis with X-ray diffraction (XRD) data is performed to unravel the structural details of the material. The findings reveal that the synthesized material exhibits a cubic crystal structure with a Pm-3m phase. The neutron diffraction results offer valuable insights into the arrangement of atoms within the lattice, contributing to a comprehensive understanding of the material’s structural properties. This research enhances our knowledge of CaSrFe0.75</sub>Co0.75</sub>Mn0.5</sub>O6−δ</sub>, with potential implications for its applications in various technological and scientific domains.展开更多
Fitting of full X-ray diffraction patterns is an effective method for quantifying abundances during X-ray diffraction (XRD) analyses. The method is based on the principal that the observed diffraction pattern is the s...Fitting of full X-ray diffraction patterns is an effective method for quantifying abundances during X-ray diffraction (XRD) analyses. The method is based on the principal that the observed diffraction pattern is the sum of the individual phases that compose the sample. By adding an internal standard (usually corundum) to both the observed patterns and to those for individual pure phases (standards), all patterns can all be normalized to an equivalent intensity based on the internal standard intensity. Using least-squares refinement, the individual phase proportions are varied until an optimal match is reached. As the fitting of full patterns uses the entire pattern, including background, disordered and amorphous phases are explicitly considered as individual phases, with their individual intensity profiles or “amorphous humps” included in the refinement. The method can be applied not only to samples that contain well-ordered materials, but it is particularly well suited for samples containing amorphous and/or disordered materials. In cases with extremely disordered materials where no crystal structure is available for Rietveld refinement or there is no unique intensity area that can be measured for a traditional RIR analysis, full-pattern fitting may be the best or only way to readily obtain quantitative results. This approach is also applicable in cases where there are several coexisting highly disordered phases. As all phases are considered as discrete individual components, abundances are not constrained to sum to 100%.展开更多
Different structure models of a long-period ordered phase in Fe-C martenstie formed during aging have been checked by computer simulation of electron diffraction(ED) patterns based on these models.The results showed t...Different structure models of a long-period ordered phase in Fe-C martenstie formed during aging have been checked by computer simulation of electron diffraction(ED) patterns based on these models.The results showed that the simulated ED pattern of γ'-FexC(Ⅱ) model proposed by the present authors is in good agreement with experimentally observed ED pattern.It was also confirmed that the incommensurate superperiod stems from the coexistence of several γ'-Fe_xC(H) phases with different superperiods.The Fe(144)C(24)(Fe6C) model proposed by Uwakweh et al.generated ED patterns remarkably different from the experimental ones.展开更多
Diffraction patterns of a rotated grating are investigated from both theoretical and experimental points of view. It is shown that as the grating rotates, the angle of deviation of each diffracted line relative to the...Diffraction patterns of a rotated grating are investigated from both theoretical and experimental points of view. It is shown that as the grating rotates, the angle of deviation of each diffracted line relative to the incident light goes through a minimum, and that the angle between any two successive diffracted lines goes through a minimum value which is the same for all adjacent diffracted lines. It is also shown that the angle between diffraction lines with n=1 and n=-1 is not sensitive to small variations of the grating from being normal to the incident light. Finally, a method is suggested for determining the line distance of a diffraction grating with high accuracy.展开更多
Transmission electron microscopy (TEM) is a very powerful technique for materials characteriza-tion, providing information relating to morphology, composition, and crystal structure. Selected area diffraction patterns...Transmission electron microscopy (TEM) is a very powerful technique for materials characteriza-tion, providing information relating to morphology, composition, and crystal structure. Selected area diffraction patterns (SADPs) are crystallographic data that can be obtained using a TEM in-strument. Conventional identification through SADP/TEM is tricky and tedious, thereby increasing the difficulty of phase identification. To establish a procedure for phase identification of known and unknown phases, in this study we examined two samples: one, a known phase, was Si with alignment;the other, unknown, was the TixOy phase at the 96.4Au-3Ni-0.6Ti interlayer/ yttria-stabilized zirconia (YSZ) interface of a steel/96.4Au-3Ni-0.6Ti interlayer/YSZ joint. The procedures for phase identification of the known and unknown phases are described herein using a series of SADPs and energy dispersive spectrometry within TEM that would be useful for general researchers.展开更多
In cooperation with figure-of-merits the Rietveld analysis can appraise both angular and intensity data of powder diffraction. In this work, X-ray diffraction pattern of Bi4(SiO4)3 was redetermined with intensity figu...In cooperation with figure-of-merits the Rietveld analysis can appraise both angular and intensity data of powder diffraction. In this work, X-ray diffraction pattern of Bi4(SiO4)3 was redetermined with intensity figure-of-merits, which qualify agreement between observed and calculated relative intensities. F30 is 158.90 (0.0059, 32), intensity figure of merit Rint is 8.7, I20(17), 8.0. The values of figure-of-merits show that the data of JCPDS cards are distorted. Both the experimental and calculated peak positions and heights are listed in detail.展开更多
Two body centered tetragonal (bet) crystal structures of α'-Fe_(16)N_2 with x=0.25, z=0.3125 (Jack-1) and x=0.222, z=0.306 (Jack-2) respectively, were analyzed theoretically with EMS software package. The simulat...Two body centered tetragonal (bet) crystal structures of α'-Fe_(16)N_2 with x=0.25, z=0.3125 (Jack-1) and x=0.222, z=0.306 (Jack-2) respectively, were analyzed theoretically with EMS software package. The simulation of diffraction patterns indicates that both diffraction patterns of the same axis in these two structures obey bcc extinction rule. The conclusion is also obtained from the analyses of the diffracted waves. α'-Fe_(16)N_2 precipitates in the diffusion layer of ion-nitrided α-iron have been studied with transmission electron microscope (TEM). We have distinctly observed the electron diffraction patterns of α'-Fe_(16)N_2 in [100], [111], [110], [011], [210], [021], [311], [113], [331] and [133] zone axes with perfect symmetry, which indicate the parallel orientation relationship with α matrix:<001>α'//<001>α'// {100}.α'// {100}tα. The analyses of diffraction patterns, which obey bcc extinction rule, verify the bct structure of α'-Fe_(16)N_2 discovered by X-ray diffraction.展开更多
A new method for pattern identification and simulation of X-ray powder diffraction data is described, which can give definite phase composition of the unknown rapidly and correctly. The method is implemented in Micros...A new method for pattern identification and simulation of X-ray powder diffraction data is described, which can give definite phase composition of the unknown rapidly and correctly. The method is implemented in Microsoft Fortran 77 for the IBM PC/XT/AT personal computer or their compatibles.展开更多
The correct use of information in science and technology is very important for its progress. Nowadays, the equipment used for the scientific and technological development provides results that are later interpreted by...The correct use of information in science and technology is very important for its progress. Nowadays, the equipment used for the scientific and technological development provides results that are later interpreted by the researchers, in most of the above mentioned equipment the results are images full of information which has to be analyzed. A powerful stage with multiple benefits in this field is the image pre-processing by means of intelligent systems, which are capable to do image analysis throwing very useful results that enhance the scientific and technological information. There are currently more than 500 functions in the computational vision specialized open source library OpenCV, which associated with the C++ programming language. These functions are used for application development in many areas of computer vision such as products inspection, medical images, safety, user's interfaces, camera calibration, stereoscopic vision and robotics. In this development and research work, by using the available functions and modifying the exposed methods, we present a proposal for signal detection in images originated in the transmission electron microscope (known as diffraction patterns), which are attached to the detailed analysis of crystalline structures used in the study of the materials science, the results show a profit of at least 18% in the detection of signs by means of the method proposed in this work.展开更多
为更好地研究硅灰对水泥胶砂耐硫酸侵蚀性能的影响,本文将硅灰按不同配合比进行试验,将水泥胶砂置于pH=1的硫酸侵蚀环境中。通过探究试样的外观、质量损失率、抗压强度损失率、硫酸侵蚀下的生成物、微观结构,并结合相关理论分析了硅灰...为更好地研究硅灰对水泥胶砂耐硫酸侵蚀性能的影响,本文将硅灰按不同配合比进行试验,将水泥胶砂置于pH=1的硫酸侵蚀环境中。通过探究试样的外观、质量损失率、抗压强度损失率、硫酸侵蚀下的生成物、微观结构,并结合相关理论分析了硅灰对水泥胶砂抗硫酸侵蚀作用的影响。实验研究表明:随着硅灰掺量的增加,水泥胶砂的抗硫酸侵蚀能力增强,XRD(x-ray diffraction)衍射表明,在硫酸侵蚀下表面生成物为二水石膏(CaSO_(4)·2H_(2)O),反应时会消耗Ca(OH)_(2),同时也会产生一定的体积膨胀;SEM(scanning electron microscope)检测表明,掺入硅灰可以提高试样的密实度,从而提高水泥胶砂的抗硫酸侵蚀性能。从宏观和微观角度综合来看,硅灰掺量为15%时的抗硫酸侵蚀性能最好。展开更多
文摘The crystal structure of CaSrFe<sub>0.75</sub>Co<sub>0.75</sub>Mn<sub>0.5</sub>O<sub>6−δ</sub> is investigated through neutron diffraction techniques in this study. The material is synthesized using a solid-state synthesis method at a temperature of 1200˚C. Neutron diffraction data is subjected to Rietveld refinement, and a comparative analysis with X-ray diffraction (XRD) data is performed to unravel the structural details of the material. The findings reveal that the synthesized material exhibits a cubic crystal structure with a Pm-3m phase. The neutron diffraction results offer valuable insights into the arrangement of atoms within the lattice, contributing to a comprehensive understanding of the material’s structural properties. This research enhances our knowledge of CaSrFe0.75</sub>Co0.75</sub>Mn0.5</sub>O6−δ</sub>, with potential implications for its applications in various technological and scientific domains.
文摘Fitting of full X-ray diffraction patterns is an effective method for quantifying abundances during X-ray diffraction (XRD) analyses. The method is based on the principal that the observed diffraction pattern is the sum of the individual phases that compose the sample. By adding an internal standard (usually corundum) to both the observed patterns and to those for individual pure phases (standards), all patterns can all be normalized to an equivalent intensity based on the internal standard intensity. Using least-squares refinement, the individual phase proportions are varied until an optimal match is reached. As the fitting of full patterns uses the entire pattern, including background, disordered and amorphous phases are explicitly considered as individual phases, with their individual intensity profiles or “amorphous humps” included in the refinement. The method can be applied not only to samples that contain well-ordered materials, but it is particularly well suited for samples containing amorphous and/or disordered materials. In cases with extremely disordered materials where no crystal structure is available for Rietveld refinement or there is no unique intensity area that can be measured for a traditional RIR analysis, full-pattern fitting may be the best or only way to readily obtain quantitative results. This approach is also applicable in cases where there are several coexisting highly disordered phases. As all phases are considered as discrete individual components, abundances are not constrained to sum to 100%.
文摘Different structure models of a long-period ordered phase in Fe-C martenstie formed during aging have been checked by computer simulation of electron diffraction(ED) patterns based on these models.The results showed that the simulated ED pattern of γ'-FexC(Ⅱ) model proposed by the present authors is in good agreement with experimentally observed ED pattern.It was also confirmed that the incommensurate superperiod stems from the coexistence of several γ'-Fe_xC(H) phases with different superperiods.The Fe(144)C(24)(Fe6C) model proposed by Uwakweh et al.generated ED patterns remarkably different from the experimental ones.
文摘Diffraction patterns of a rotated grating are investigated from both theoretical and experimental points of view. It is shown that as the grating rotates, the angle of deviation of each diffracted line relative to the incident light goes through a minimum, and that the angle between any two successive diffracted lines goes through a minimum value which is the same for all adjacent diffracted lines. It is also shown that the angle between diffraction lines with n=1 and n=-1 is not sensitive to small variations of the grating from being normal to the incident light. Finally, a method is suggested for determining the line distance of a diffraction grating with high accuracy.
文摘Transmission electron microscopy (TEM) is a very powerful technique for materials characteriza-tion, providing information relating to morphology, composition, and crystal structure. Selected area diffraction patterns (SADPs) are crystallographic data that can be obtained using a TEM in-strument. Conventional identification through SADP/TEM is tricky and tedious, thereby increasing the difficulty of phase identification. To establish a procedure for phase identification of known and unknown phases, in this study we examined two samples: one, a known phase, was Si with alignment;the other, unknown, was the TixOy phase at the 96.4Au-3Ni-0.6Ti interlayer/ yttria-stabilized zirconia (YSZ) interface of a steel/96.4Au-3Ni-0.6Ti interlayer/YSZ joint. The procedures for phase identification of the known and unknown phases are described herein using a series of SADPs and energy dispersive spectrometry within TEM that would be useful for general researchers.
文摘In cooperation with figure-of-merits the Rietveld analysis can appraise both angular and intensity data of powder diffraction. In this work, X-ray diffraction pattern of Bi4(SiO4)3 was redetermined with intensity figure-of-merits, which qualify agreement between observed and calculated relative intensities. F30 is 158.90 (0.0059, 32), intensity figure of merit Rint is 8.7, I20(17), 8.0. The values of figure-of-merits show that the data of JCPDS cards are distorted. Both the experimental and calculated peak positions and heights are listed in detail.
文摘Two body centered tetragonal (bet) crystal structures of α'-Fe_(16)N_2 with x=0.25, z=0.3125 (Jack-1) and x=0.222, z=0.306 (Jack-2) respectively, were analyzed theoretically with EMS software package. The simulation of diffraction patterns indicates that both diffraction patterns of the same axis in these two structures obey bcc extinction rule. The conclusion is also obtained from the analyses of the diffracted waves. α'-Fe_(16)N_2 precipitates in the diffusion layer of ion-nitrided α-iron have been studied with transmission electron microscope (TEM). We have distinctly observed the electron diffraction patterns of α'-Fe_(16)N_2 in [100], [111], [110], [011], [210], [021], [311], [113], [331] and [133] zone axes with perfect symmetry, which indicate the parallel orientation relationship with α matrix:<001>α'//<001>α'// {100}.α'// {100}tα. The analyses of diffraction patterns, which obey bcc extinction rule, verify the bct structure of α'-Fe_(16)N_2 discovered by X-ray diffraction.
文摘A new method for pattern identification and simulation of X-ray powder diffraction data is described, which can give definite phase composition of the unknown rapidly and correctly. The method is implemented in Microsoft Fortran 77 for the IBM PC/XT/AT personal computer or their compatibles.
文摘The correct use of information in science and technology is very important for its progress. Nowadays, the equipment used for the scientific and technological development provides results that are later interpreted by the researchers, in most of the above mentioned equipment the results are images full of information which has to be analyzed. A powerful stage with multiple benefits in this field is the image pre-processing by means of intelligent systems, which are capable to do image analysis throwing very useful results that enhance the scientific and technological information. There are currently more than 500 functions in the computational vision specialized open source library OpenCV, which associated with the C++ programming language. These functions are used for application development in many areas of computer vision such as products inspection, medical images, safety, user's interfaces, camera calibration, stereoscopic vision and robotics. In this development and research work, by using the available functions and modifying the exposed methods, we present a proposal for signal detection in images originated in the transmission electron microscope (known as diffraction patterns), which are attached to the detailed analysis of crystalline structures used in the study of the materials science, the results show a profit of at least 18% in the detection of signs by means of the method proposed in this work.
文摘为更好地研究硅灰对水泥胶砂耐硫酸侵蚀性能的影响,本文将硅灰按不同配合比进行试验,将水泥胶砂置于pH=1的硫酸侵蚀环境中。通过探究试样的外观、质量损失率、抗压强度损失率、硫酸侵蚀下的生成物、微观结构,并结合相关理论分析了硅灰对水泥胶砂抗硫酸侵蚀作用的影响。实验研究表明:随着硅灰掺量的增加,水泥胶砂的抗硫酸侵蚀能力增强,XRD(x-ray diffraction)衍射表明,在硫酸侵蚀下表面生成物为二水石膏(CaSO_(4)·2H_(2)O),反应时会消耗Ca(OH)_(2),同时也会产生一定的体积膨胀;SEM(scanning electron microscope)检测表明,掺入硅灰可以提高试样的密实度,从而提高水泥胶砂的抗硫酸侵蚀性能。从宏观和微观角度综合来看,硅灰掺量为15%时的抗硫酸侵蚀性能最好。