The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform
Toshiro Endo - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of surface and subsurface cracks on nano-scale machined brittle materials by scanning force Microscope and scanning Laser Microscope
Surface & Coatings Technology, 2003Co-Authors: Masayoshi Nakamura, Tsunetaka Sumomogi, Toshiro EndoAbstract:Nano-scale machining by ultra precision grinding and cutting, known as ductile mode machining, has the potential of overcoming limitations of conventional machining technology. In this study, the nano-scale layers of single crystal silicon and glass surface were machined by a sharply pointed diamond tool, and the subsurface cracks as well as the surface cracks were observed by a scanning force Microscope and a scanning Laser Microscope. The transition point determined by the subsurface cracks is found to be shallower than that by the surface cracks. Therefore the evaluation of the subsurface cracks is important especially in finish machining.
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Evaluation of surface and subsurface cracks in nanoscale-machined single-crystal silicon by scanning force Microscope and scanning Laser Microscope
Materials Characterization, 2002Co-Authors: Tsunetaka Sumomogi, Masayoshi Nakamura, Toshiro Endo, Takayuki Goto, Satoshi KajiAbstract:Abstract Studies of nanoscale machining of brittle materials, such as silicon, have come into prominence in recent years. Material removal with plastic deformation, known as ductile mode machining, has been achieved by a very small depth of cut. When surface cracks occurred with increasing cut depth, the machining has been commonly considered to be of brittle mode. In the present study, the ductile–brittle transition point in the nanoscale machining of single-crystal silicon was examined by the observations not only on the surface cracks but also on the subsurface cracks. A scanning force Microscope was used to measure the depth of the grooves and to observe the surface cracks. The distance from the surfaces to the deepest point of the subsurface cracks on obliquely sectioned and then etched surfaces were measured by a scanning Laser Microscope. The transition point determined by the subsurface cracks was found to occur at a shallower depth of cut compared with the transition point from the surface cracks. Therefore, evaluation of subsurface cracks is important especially in the finish shape of machining.
C.d. Wright - One of the best experts on this subject based on the ideXlab platform.
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A scanning Laser Microscope system to observe static and dynamic magnetic domain behavior
IEEE Transactions on Instrumentation and Measurement, 2002Co-Authors: W.w. Clegg, David Jenkins, J. Windmill, N. Fry, N. Helian, Ron Atkinson, W.r. Hendren, C.d. WrightAbstract:Scanning Laser Microscopes (SLMs) have been used to characterize the magnetic properties of materials for some time. The first SLM built was a purely static system capable of imaging magnetic domains. Dynamic capability was introduced with the development of the R-Theta Microscope. However, this Microscope utilizes a rotating drive. A scanning Laser Microscope has been designed to observe the dynamic behavior of domain switching during the thermomagnetic write process and the subsequent magnetization state (domain orientation) in stationary media, without the requirement for a rotating drive. It may also be used to write to the magneto-optic (MO) disk material thermomagnetically prior to imaging. Images are derived from the longitudinal and polar magneto-optic Kerr effects. In this paper, the different configurations for imaging are described and some initial images are presented.
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A short wavelength R-/spl theta/ scanning Laser Microscope and optical disc tester for the characterization of optical recording media
IEEE Transactions on Magnetics, 1995Co-Authors: N.a.e. Heyes, C.d. Wright, W.w. Clegg, J. ZhaoAbstract:The design and applications of a novel, short wavelength, combined R-/spl theta/ scanning Laser Microscope (SLM) and optical disc tester that is used for the imaging of recorded bit structures and the characterization of optical recording media is described. The instrument is optimised for magneto-optical recording applications and provides images with sub-micron resolution. Imaging is achieved by focusing the light from an argon-ion Laser (514 nm or 488 nm wavelength) to a diffraction limited spot on the surface of a rotating sample to generate the line scan, whilst moving the objective lens slowly in the radial direction to generate the frame scan.
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Observations of magneto‐optic phase contrast using a scanning Laser Microscope
Journal of Applied Physics, 1991Co-Authors: N.a.e. Heyes, C.d. Wright, W.w. CleggAbstract:A scanning Laser Microscope (SLM) has been built which is capable of observing magnetic structure via ‘‘conventional’’ Kerr imaging techniques and a ‘‘novel’’ magneto‐optic phase contrast approach. This latter contrast mode highlights magnetic transitions, rather than domains themselves. In this paper we present results of observations in TbFeCo samples using this phase contrast technique and assess its possible application as a read‐out mechanism for magneto‐optic recording systems.
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Scanning Laser Microscope studies of the overwrite characteristics of TbFeCo films using magnetic field modulation
Journal of Applied Physics, 1991Co-Authors: C.d. Wright, N.a.e. Heyes, W.w. CleggAbstract:In the search for a directly overwritable magneto‐optic recording system, that based upon the magnetic field modulation method looks quite favorable. This approach also enables submicron domains to be written, so increasing attainable storage densities. Here we report on the results of such field modulation studies performed in situ using our magneto‐optical scanning Laser Microscope (SLM). Bit patterns were recorded in TbFeCo films by continuous Laser irradiation coupled with the application of an alternating magnetic field supplied by a small, purpose built electromagnet having a peak field of approximately 4 kOe. The recorded domain structures were then imaged using the SLM in its polar Kerr mode. Recorded patterns were overwritten and the resulting bit patterns observed.
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Development of a scanning Laser Microscope for magneto-optic studies of thin magnetic films
Journal of Magnetism and Magnetic Materials, 1991Co-Authors: W.w. Clegg, N.a.e. Heyes, Ernie W. Hill, C.d. WrightAbstract:Abstract A magneto-optic scanning Laser Microscope has been built which is capable of observing the magnetic domain structure present in materials which exhibit the Kerr (polar and longitudinal) and Faraday magneto-optical effects. The samples are not specially coated to improve the Kerr contrast, images being formed of the domain structures in the “as produced” samples. The instrument is also capable of observing nonmagnetic contrast. In addition the Microscope may be used, together with a high-power Ar ion Laser, as a thermo-magneto-optic bit writer
Oliver Trepte - One of the best experts on this subject based on the ideXlab platform.
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An optical spectrometer for a confocal scanning Laser Microscope
Scanning, 2006Co-Authors: Oliver TrepteAbstract:An optical spectrometer for the visible range has been developed for the confocal scanning Laser Microscope (CSLM) Phoibos 1000. The spectrometer records information from a single point or a user-defined region within the Microscope specimen. A prism disperses the spectral components of the recorded light over a linear CCD photodiode array with 256 elements. A regulated cooling unit cools the diode array, thereby reducing the detector dark current to a level, which allows integration times of up to 60 s. The spectral resolving power, λ/Δλ, ranges from 400 at λ = 375 nm to 100 at λ = 700 nm. Since the entrance aperture of the spectrometer has the same diameter as the detector aperture of the CSLM, the three-dimensional spatial resolution for spectrometer readings is equivalent to that of conventional confocal scanning, that is, down to 0.2 μm lateral and 0.8 μm axial resolution with an N.A.=1.3 objective.
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Enhanced scanning control in a confocal scanning Laser Microscope
Scanning, 2006Co-Authors: Oliver TrepteAbstract:A fast and flexible scanning unit, allowing scanning rates of more than 1 kHz over regions identified in a specimen, has been developed and evaluated. This scanning unit replaces the original scanning unit in the Phoibos confocal scanning Laser Microscope and features full backward compatibility, while at the same time allowing fast and flexible scanning modes, such as point scanning, line scanning, and scanning along user-selected closed curves. The scanning unit uses two galvanometer-mounted mirrors for scanning. A standard procedure for recordings with this scanning unit would be to scan an overview image with conventional raster scanning to identify a region of interest, mark a point, a line, or a closed curve over this region, and to start the scanner. An iterating algorithm then calculates the waveforms needed by the scanner to follow the identified curves with pixel precision. With this scanning unit and its controlling software, experiments demanding time-resolved recordings within the millisecond range can be performed. Repetition rates up to > 1 kHz for line scanning and curve scanning, and > 100 kHz for point scanning are obtainable. This allows time-resolved studies of fast reactions in living tissue to be performed with the spatial resolution and signal-to-noise ratio obtainable with a point scanning confocal Microscope.
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Optical spectrometer for a confocal scanning Laser Microscope with applications in porphyrin-containing specimens
Three-Dimensional Microscopy: Image Acquisition and Processing II, 1995Co-Authors: Oliver Trepte, Ingrid Rokahr, Stefan Andersson-engelsAbstract:A spectrometer has been developed for the Phoibos confocal scanning Laser Microscope. With this spectrometer, spectral information from a single point, or a user defined region, within the Microscope specimen, can be recorded. The spectrometer is based on an integrated spectrometer module, manufactured by Carl Zeiss, Germany. The module takes its light input signal through a fiber with an entrance diameter of 0.5 mm. Integrated in the spectrometer module are dispersing optics, based on a grating, as well as preamplifier electronics. A regulated cooling unit keeps the detector at -4 degree(s)C, thereby allowing longer integration times. The spectral resolution, defined as the minimum distance between two peaks (Rayleigh criterion) is approximately 10 nm. The entrance of the optical fiber is employed as a pinhole. With different magnification in the optical path leading the light to the spectrometer, the entrance can either be employed as a pinhole of the same size as the one used during conventional confocal scanning, i.e. the 3D spatial resolution will be retained, or the light throughput can be increased at the expense of optical resolution. With the described equipment, studies of rodent lung and liver specimens containing porphyrins have been made. Organs from animals injected with (delta) -amino levulinic acid, a precursor to protoporphyrin IX and haem in the haem cycle, have been studied. Spectroscopic detection is necessary in order to separate the porphyrin signal from other fluorescent components in the specimen.
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Computer control for a galvanometer scanner in a confocal scanning Laser Microscope
Optical Engineering, 1994Co-Authors: Oliver Trepte, Anders LiljeborgAbstract:A digital control has been developed for a galvanometer scanner used in a confocal scanning Laser Microscope. The galvanometer scanner utilizes a microprocessor-controlled scan control unit, able to produce repetitive analog waveforms and digital control signals, and to record analog and digital signals. The scan control unit outputs a sawtooth waveform to the galvanometer, records the position signal from the position sensor in the galvanometer, and uses this information to calculate the timing needed to trigger the reading of 1024 x 1024 equally spaced pixels in the specimen. The galvanometer may be statically positioned at an arbitrarily chosen pixel, thereby allowing recording of data from a point within the Microscope specimen for an arbitrary length of time. This makes it possible to record spectral information or to measure fluorescent lifetimes at a single point.
Akihisa Inoue - One of the best experts on this subject based on the ideXlab platform.
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In situ analysis of the thermal behavior in the Zr-based multi-component metallic thin film by pulsed Laser deposition combined with UHV-Laser Microscope system
Materials Science and Engineering B-advanced Functional Solid-state Materials, 2007Co-Authors: Yuji Matsumoto, Miki Hiraoka, Masao Katayama, Seiichi Hata, Mikio Fukuhara, Takeshi Wada, Hisamichi Kimura, Akihisa InoueAbstract:Abstract The thermal behavior of the Zr-based multi-component metallic thin films was investigated under an atmospheric N2 condition by using pulsed Laser deposition (PLD)-combined with in situ Laser Microscope (LM) system. The Zr-based multi-component metallic thin films were prepared in amorphous by PLD with a stoichiometric target of the Zr-based metallic glass. By comprehensive study with ex situ analyses such as XRD, SEM and EPMA techniques, it was found that the gradual formation of Zr2Ni alloy particles occurred above 500 °C, and subsequently the inhomogeneous contrast, probably owing to the partial formation of ZrO2 on the film surface appeared at high temperature.
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In situ observation of solidification behavior in undercooled Pd–Cu–Ni–P alloy by using a confocal scanning Laser Microscope
Acta Materialia, 2001Co-Authors: J.-h Kim, S.-g Kim, Akihisa InoueAbstract:Abstract In the undercooled melt of Pd 40 Cu 30 Ni 10 P 20 alloy, the solidification behavior including the nucleation and growth of crystals at the micrometer level has been observed in situ by use of a confocal scanning Laser Microscope combined with an infrared image furnace. The Pd 40 Cu 30 Ni 10 P 20 alloy specimens were cooled from the liquid state to various undercooled states under a helium gas flow. Images of solidification progress were obtained by the charge-coupled device image sensor of the confocal scanning Laser Microscope. Depending on the degree of undercooling, the morphology of the solidification front changed among various types: faceted front, columnar dendritic front, cellular grain and equiaxed grain, etc. The velocities of the solid–liquid interface were measured to be 10 −5 –10−7 m/s, which are at least two orders of magnitude higher than the theoretical crystal growth rates. Combining the morphologies observed in the three undercooling regimes and their solidification behaviors, we conclude that phase separation takes place in the undercooled molten Pd 40 Cu 30 Ni 10 P 20 alloy. The continuous-cooling–transformation (CCT) diagram was derived from the experimental time–temperature-transformation diagram constructed from solidification onset times under various isothermal annealing conditions. The CCT diagram suggests that the critical cooling rate for glassy solidification is about 1.8 K/s, which is in agreement with previous calorimetric findings.
W.w. Clegg - One of the best experts on this subject based on the ideXlab platform.
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A scanning Laser Microscope system to observe static and dynamic magnetic domain behavior
IEEE Transactions on Instrumentation and Measurement, 2002Co-Authors: W.w. Clegg, David Jenkins, J. Windmill, N. Fry, N. Helian, Ron Atkinson, W.r. Hendren, C.d. WrightAbstract:Scanning Laser Microscopes (SLMs) have been used to characterize the magnetic properties of materials for some time. The first SLM built was a purely static system capable of imaging magnetic domains. Dynamic capability was introduced with the development of the R-Theta Microscope. However, this Microscope utilizes a rotating drive. A scanning Laser Microscope has been designed to observe the dynamic behavior of domain switching during the thermomagnetic write process and the subsequent magnetization state (domain orientation) in stationary media, without the requirement for a rotating drive. It may also be used to write to the magneto-optic (MO) disk material thermomagnetically prior to imaging. Images are derived from the longitudinal and polar magneto-optic Kerr effects. In this paper, the different configurations for imaging are described and some initial images are presented.
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Observations of magneto‐optic phase contrast using a scanning Laser Microscope
Journal of Applied Physics, 1991Co-Authors: N.a.e. Heyes, C.d. Wright, W.w. CleggAbstract:A scanning Laser Microscope (SLM) has been built which is capable of observing magnetic structure via ‘‘conventional’’ Kerr imaging techniques and a ‘‘novel’’ magneto‐optic phase contrast approach. This latter contrast mode highlights magnetic transitions, rather than domains themselves. In this paper we present results of observations in TbFeCo samples using this phase contrast technique and assess its possible application as a read‐out mechanism for magneto‐optic recording systems.
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Scanning Laser Microscope studies of the overwrite characteristics of TbFeCo films using magnetic field modulation
Journal of Applied Physics, 1991Co-Authors: C.d. Wright, N.a.e. Heyes, W.w. CleggAbstract:In the search for a directly overwritable magneto‐optic recording system, that based upon the magnetic field modulation method looks quite favorable. This approach also enables submicron domains to be written, so increasing attainable storage densities. Here we report on the results of such field modulation studies performed in situ using our magneto‐optical scanning Laser Microscope (SLM). Bit patterns were recorded in TbFeCo films by continuous Laser irradiation coupled with the application of an alternating magnetic field supplied by a small, purpose built electromagnet having a peak field of approximately 4 kOe. The recorded domain structures were then imaged using the SLM in its polar Kerr mode. Recorded patterns were overwritten and the resulting bit patterns observed.
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Development of a scanning Laser Microscope for magneto-optic studies of thin magnetic films
Journal of Magnetism and Magnetic Materials, 1991Co-Authors: W.w. Clegg, N.a.e. Heyes, Ernie W. Hill, C.d. WrightAbstract:Abstract A magneto-optic scanning Laser Microscope has been built which is capable of observing the magnetic domain structure present in materials which exhibit the Kerr (polar and longitudinal) and Faraday magneto-optical effects. The samples are not specially coated to improve the Kerr contrast, images being formed of the domain structures in the “as produced” samples. The instrument is also capable of observing nonmagnetic contrast. In addition the Microscope may be used, together with a high-power Ar ion Laser, as a thermo-magneto-optic bit writer
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A scanning Laser Microscope system to observe static and dynamic magnetic domain behaviour
Proceedings of the 17th IEEE Instrumentation and Measurement Technology Conference [Cat. No. 00CH37066], 1Co-Authors: W.w. Clegg, David Jenkins, J. Windmill, N. FryAbstract:A scanning Laser Microscope has been designed to observe the dynamic behaviour of domain switching during the thermo-magnetic write process and the subsequent magnetisation state (domain orientation) in thin-films and devices. It will also be used to write to magneto-optic (MO) disk material thermo-magnetically prior to imaging. Images are derived from the longitudinal and polar magneto-optic Kerr effects, which are wavelength dependent, using the appropriate Laser wavelength. In this paper the different configurations for imaging are described, and some initial images are presented.
