The Experts below are selected from a list of 48 Experts worldwide ranked by ideXlab platform
Robert M Glaeser - One of the best experts on this subject based on the ideXlab platform.
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design of a hybrid double sideband single sideband schlieren Objective Aperture suitable for electron microscopy
Ultramicroscopy, 2011Co-Authors: Bart Buijsse, Frank M H M Van Laarhoven, Andreas K Schmid, Rossana Cambie, Stefano Cabrini, Jian Jin, Robert M GlaeserAbstract:Abstract A novel design is described for an Aperture that blocks a half-plane of the electron diffraction pattern out to a desired scattering angle, and then – except for a narrow support beam – transmits all of the scattered electrons beyond that angle. Our proposed tulip-shaped design is thus a hybrid between the single-sideband (ssb) Aperture, which blocks a full half-plane of the diffraction pattern, and the conventional (i.e. fully open) double-sideband (dsb) Aperture. The benefits of this hybrid design include the fact that such an Aperture allows one to obtain high-contrast images of weak-phase objects with the Objective lens set to Scherzer defocus. We further demonstrate that such Apertures can be fabricated from thin-foil materials by milling with a focused ion beam (FIB), and that such Apertures are fully compatible with the requirements of imaging out to a resolution of at least 0.34 nm. As is known from earlier work with single-sideband Apertures, however, the edge of such an Aperture can introduce unwanted, electrostatic phase shifts due to charging. The principal requirement for using such an Aperture in a routine data-collection mode is thus to discover appropriate materials, protocols for fabrication and processing and conditions of use such that the hybrid Aperture remains free of charging over long periods of time.
Bart Buijsse - One of the best experts on this subject based on the ideXlab platform.
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design of a hybrid double sideband single sideband schlieren Objective Aperture suitable for electron microscopy
Ultramicroscopy, 2011Co-Authors: Bart Buijsse, Frank M H M Van Laarhoven, Andreas K Schmid, Rossana Cambie, Stefano Cabrini, Jian Jin, Robert M GlaeserAbstract:Abstract A novel design is described for an Aperture that blocks a half-plane of the electron diffraction pattern out to a desired scattering angle, and then – except for a narrow support beam – transmits all of the scattered electrons beyond that angle. Our proposed tulip-shaped design is thus a hybrid between the single-sideband (ssb) Aperture, which blocks a full half-plane of the diffraction pattern, and the conventional (i.e. fully open) double-sideband (dsb) Aperture. The benefits of this hybrid design include the fact that such an Aperture allows one to obtain high-contrast images of weak-phase objects with the Objective lens set to Scherzer defocus. We further demonstrate that such Apertures can be fabricated from thin-foil materials by milling with a focused ion beam (FIB), and that such Apertures are fully compatible with the requirements of imaging out to a resolution of at least 0.34 nm. As is known from earlier work with single-sideband Apertures, however, the edge of such an Aperture can introduce unwanted, electrostatic phase shifts due to charging. The principal requirement for using such an Aperture in a routine data-collection mode is thus to discover appropriate materials, protocols for fabrication and processing and conditions of use such that the hybrid Aperture remains free of charging over long periods of time.
Stuart R. Stock - One of the best experts on this subject based on the ideXlab platform.
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Transmission electron microscopy characterization of macromolecular domain cavities and microstructure of single-crystal calcite tooth plates of the sea urchin Lytechinus variegatus.
Journal of Structural Biology, 2005Co-Authors: J.s. Robach, Stuart R. StockAbstract:The calcite plates and prisms in Lytechinus variegatus teeth form a complex biocomposite and employ a myriad of strengthening and toughening strategies. These crystal elements have macromolecule-containing internal cavities that may act to prevent cleavage. Transmission electron microscopy employing a small Objective Aperture was used to quantify several characteristics of these cavities. Cavity diameters ranged from 10 to 225 nm, the mean cavity diameter was between 50 and 60 nm, and cavities comprised approximately 20% of the volume of the crystal. Some cavities exhibited faceting and trace analysis identified these planes as being predominately of {1014} type. Through focus series of micrographs show the cavities were homogeneously distributed throughout the foil. The electron beam decomposed a substance within cavities and this suggests that these cavities are filled with a hydrated organic phase.
Jian Jin - One of the best experts on this subject based on the ideXlab platform.
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design of a hybrid double sideband single sideband schlieren Objective Aperture suitable for electron microscopy
Ultramicroscopy, 2011Co-Authors: Bart Buijsse, Frank M H M Van Laarhoven, Andreas K Schmid, Rossana Cambie, Stefano Cabrini, Jian Jin, Robert M GlaeserAbstract:Abstract A novel design is described for an Aperture that blocks a half-plane of the electron diffraction pattern out to a desired scattering angle, and then – except for a narrow support beam – transmits all of the scattered electrons beyond that angle. Our proposed tulip-shaped design is thus a hybrid between the single-sideband (ssb) Aperture, which blocks a full half-plane of the diffraction pattern, and the conventional (i.e. fully open) double-sideband (dsb) Aperture. The benefits of this hybrid design include the fact that such an Aperture allows one to obtain high-contrast images of weak-phase objects with the Objective lens set to Scherzer defocus. We further demonstrate that such Apertures can be fabricated from thin-foil materials by milling with a focused ion beam (FIB), and that such Apertures are fully compatible with the requirements of imaging out to a resolution of at least 0.34 nm. As is known from earlier work with single-sideband Apertures, however, the edge of such an Aperture can introduce unwanted, electrostatic phase shifts due to charging. The principal requirement for using such an Aperture in a routine data-collection mode is thus to discover appropriate materials, protocols for fabrication and processing and conditions of use such that the hybrid Aperture remains free of charging over long periods of time.
Stefano Cabrini - One of the best experts on this subject based on the ideXlab platform.
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design of a hybrid double sideband single sideband schlieren Objective Aperture suitable for electron microscopy
Ultramicroscopy, 2011Co-Authors: Bart Buijsse, Frank M H M Van Laarhoven, Andreas K Schmid, Rossana Cambie, Stefano Cabrini, Jian Jin, Robert M GlaeserAbstract:Abstract A novel design is described for an Aperture that blocks a half-plane of the electron diffraction pattern out to a desired scattering angle, and then – except for a narrow support beam – transmits all of the scattered electrons beyond that angle. Our proposed tulip-shaped design is thus a hybrid between the single-sideband (ssb) Aperture, which blocks a full half-plane of the diffraction pattern, and the conventional (i.e. fully open) double-sideband (dsb) Aperture. The benefits of this hybrid design include the fact that such an Aperture allows one to obtain high-contrast images of weak-phase objects with the Objective lens set to Scherzer defocus. We further demonstrate that such Apertures can be fabricated from thin-foil materials by milling with a focused ion beam (FIB), and that such Apertures are fully compatible with the requirements of imaging out to a resolution of at least 0.34 nm. As is known from earlier work with single-sideband Apertures, however, the edge of such an Aperture can introduce unwanted, electrostatic phase shifts due to charging. The principal requirement for using such an Aperture in a routine data-collection mode is thus to discover appropriate materials, protocols for fabrication and processing and conditions of use such that the hybrid Aperture remains free of charging over long periods of time.
