Microscopy, 2014, Vol. 63, No. S1
PLENARY LECTURE Recent Progress in Electromagnetic Field Mapping at the Nanoscale R. E. Dunin-Borkowski Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich, Germany
References 1. Iijima S, (1991) “Helical micro-tubules of graphitic carbon”, Nature, 345, 56–58 2. Iijima S, Ichihashi T, (1993) “Single shell carbon nanotubes of one nanometer diameter” Nature 363, 503–605 3. Iijima S, (1971) “High resolution electron microscopy of crystal lattice of titanium-niobium oxide”, J.Appl.Phys., 42, 5891–5893 4. Iijima S, (1977) “Observation of single and clusters of atoms in bright field electron microscopy“, Optik, 48, 193–214. doi: 10.1093/jmicro/dfu097
Single molecule imaging expanded to macroscopic level by computer simulation
References 1. Beleggia M.T., Kasama R.E. Dunin-Borkowski: Ultramicroscopy Vol. 110 (2010), p. 425 2. Pozzi G., Migunov V., Tavabi A.H., Dwyer C., Kovács A., Caron J., Diehle P, Savenko A., Beleggia M., Kasama T., London A., Kelly T.F., Larson D.J.M. Farle are thanked for valuable contributions to this work. doi: 10.1093/jmicro/dfu085 Careful observation is the first thing to do in science Sumio Iijima Graduate School of Science and Technology, Meijo University, National Institute of Advanced Industrial Science and Technology/ Nanotube Research Center, and NEC Modern industry is based largely on “Mono-tukuri” - making things. A particular issue is of finding new materials. One of examples is
Toshio Yanagida Graduate School of Frontier Biosciences, Osaka University, QBiC & SCLS (RIKEN), CiNet (NICT) Biological machines work skillfully with extremely low energy cost. For example, a human brain consumes only one watt (difference between working and resting states) and a cell does 1p (1×10−12) watts. On the other hand, a super computer “Kei”, which is the best one in Japan, consumes 20 M (2×107) watts. How can the biological machines function so skillfully? We have studied the mechanism of molecular motor, myosin that is responsible for the muscle contraction. For this, we have developed a single molecule nano-detection technique, which allows us to directly observe and manipulate a single myosin molecule of tens of nanometers in size in solution. The movement of myosin motor was expected to be accurate and mechanistic based on an analogy to a man-made machine. However, our
Downloaded from http://jmicro.oxfordjournals.org/ at Selcuk University on February 9, 2015
Recent studies of electromagnetic fields using off-axis electron holography in the transmission electron microscope (TEM) have involved the use of specimen holders with multiple electrical contacts to examine working devices, the application of holographic tomography to record three-dimensional potentials and the use of ultra-stable TEMs and phase-shifting holography to improve phase sensitivity. Here, we highlight a selection of the latest examples of our use of off-axis electron holography to quantify electromagnetic fields within and around novel device structures. We have succeeded in measuring the magnetic field of a nanoscale current-carrying wire. As a current flowing parallel to the plane of an untilted TEM specimen produces no net magnetic phase shift, we examined a free-standing wire that contained a short nano-fabricated segment oriented parallel to the electron beam direction. The azimuthal magnetic field around this short section of wire resulted in a tuneable phase distribution that could be varied by changing the current in the wire. Different regions of such a wire could in principle be used to apply in-plane or out-of-plane magnetic fields to closely-adjacent nanomagnets in the TEM. We have measured the electrostatic potentials of two collinear electrically-biased metallic needles. Phase images were analysed both through comparisons with simulations and by using a model-independent approach involving contour integration of the phase gradient [1]. Interestingly, spectacular caustic phenomena containing fold, butterfly and elliptic umbilic catastrophes were observed in defocused bright-field TEM images of the same electrically-biased metallic needles. The main features in the caustics were found to depend sensitively on defocus, on the applied voltage between the needles and on their separation. We are currently working on the reconstruction of three-dimensional magnetization distributions inside materials directly from tilt series of phase images recorded using electron holography. Forward simulations are used in an iterative algorithm to solve the inverse problems from tomographic tilt series of phase images. The use of such model-based approaches avoids many of the artefacts that result from using classical tomographic techniques, while allowing additional constraints to be incorporated [2].
carbon nanotube which has been the most popular in the fields of nanoscience and nanotechnology. I would like to speak about the story of discovery of the carbon nanotube as its discoverer [1, 2]. Diamond, pencil-lead, charcoal, graphite and carbon nanotube, they are made of carbon atoms, and their morphological differences result from how the carbon atoms are connected each other to form a solid、The carbon nanotube has basically the same atomic structure as graphite but it forms a nanometer-sized tube with a diameter of 1∼3 nanometer. Because of this unique morphology the carbon nanotube shows unusual electrical and mechanical properties not seen in conventional graphite. These properties make possible to build a transistor, a touch screen of smart phones, and others in electronics industry. A kind of graphene, its inventors were awarded the Nobel Prize in physics in 2010, is similar to the carbon nanotube. I found accidentally the carbon nanotube but actually its discovery was a consequence of my long experiences with high resolution electron microscopy. I was curious to see ultimate crystal structures that should be built up by atoms. So visualization of individual atoms under the microscope is an attractive subject to work with and many microscopists challenged to this goal. My effort has been rewarded in successful observation of individual atoms in the 1970 [3, 4]. Such curiosity and dedication have been connected to the discovery of carbon nanotube. My talk will also cover the latest research activities in nanocarbon materials research that have been done by modern high resolution electron microscopes.
PLENARY LECTURE Recent Progress in Electromagnetic Field Mapping at the Nanoscale R. E. Dunin-Borkowski Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich, Germany
References 1. Iijima S, (1991) “Helical micro-tubules of graphitic carbon”, Nature, 345, 56–58 2. Iijima S, Ichihashi T, (1993) “Single shell carbon nanotubes of one nanometer diameter” Nature 363, 503–605 3. Iijima S, (1971) “High resolution electron microscopy of crystal lattice of titanium-niobium oxide”, J.Appl.Phys., 42, 5891–5893 4. Iijima S, (1977) “Observation of single and clusters of atoms in bright field electron microscopy“, Optik, 48, 193–214. doi: 10.1093/jmicro/dfu097
Single molecule imaging expanded to macroscopic level by computer simulation
References 1. Beleggia M.T., Kasama R.E. Dunin-Borkowski: Ultramicroscopy Vol. 110 (2010), p. 425 2. Pozzi G., Migunov V., Tavabi A.H., Dwyer C., Kovács A., Caron J., Diehle P, Savenko A., Beleggia M., Kasama T., London A., Kelly T.F., Larson D.J.M. Farle are thanked for valuable contributions to this work. doi: 10.1093/jmicro/dfu085 Careful observation is the first thing to do in science Sumio Iijima Graduate School of Science and Technology, Meijo University, National Institute of Advanced Industrial Science and Technology/ Nanotube Research Center, and NEC Modern industry is based largely on “Mono-tukuri” - making things. A particular issue is of finding new materials. One of examples is
Toshio Yanagida Graduate School of Frontier Biosciences, Osaka University, QBiC & SCLS (RIKEN), CiNet (NICT) Biological machines work skillfully with extremely low energy cost. For example, a human brain consumes only one watt (difference between working and resting states) and a cell does 1p (1×10−12) watts. On the other hand, a super computer “Kei”, which is the best one in Japan, consumes 20 M (2×107) watts. How can the biological machines function so skillfully? We have studied the mechanism of molecular motor, myosin that is responsible for the muscle contraction. For this, we have developed a single molecule nano-detection technique, which allows us to directly observe and manipulate a single myosin molecule of tens of nanometers in size in solution. The movement of myosin motor was expected to be accurate and mechanistic based on an analogy to a man-made machine. However, our
Downloaded from http://jmicro.oxfordjournals.org/ at Selcuk University on February 9, 2015
Recent studies of electromagnetic fields using off-axis electron holography in the transmission electron microscope (TEM) have involved the use of specimen holders with multiple electrical contacts to examine working devices, the application of holographic tomography to record three-dimensional potentials and the use of ultra-stable TEMs and phase-shifting holography to improve phase sensitivity. Here, we highlight a selection of the latest examples of our use of off-axis electron holography to quantify electromagnetic fields within and around novel device structures. We have succeeded in measuring the magnetic field of a nanoscale current-carrying wire. As a current flowing parallel to the plane of an untilted TEM specimen produces no net magnetic phase shift, we examined a free-standing wire that contained a short nano-fabricated segment oriented parallel to the electron beam direction. The azimuthal magnetic field around this short section of wire resulted in a tuneable phase distribution that could be varied by changing the current in the wire. Different regions of such a wire could in principle be used to apply in-plane or out-of-plane magnetic fields to closely-adjacent nanomagnets in the TEM. We have measured the electrostatic potentials of two collinear electrically-biased metallic needles. Phase images were analysed both through comparisons with simulations and by using a model-independent approach involving contour integration of the phase gradient [1]. Interestingly, spectacular caustic phenomena containing fold, butterfly and elliptic umbilic catastrophes were observed in defocused bright-field TEM images of the same electrically-biased metallic needles. The main features in the caustics were found to depend sensitively on defocus, on the applied voltage between the needles and on their separation. We are currently working on the reconstruction of three-dimensional magnetization distributions inside materials directly from tilt series of phase images recorded using electron holography. Forward simulations are used in an iterative algorithm to solve the inverse problems from tomographic tilt series of phase images. The use of such model-based approaches avoids many of the artefacts that result from using classical tomographic techniques, while allowing additional constraints to be incorporated [2].
carbon nanotube which has been the most popular in the fields of nanoscience and nanotechnology. I would like to speak about the story of discovery of the carbon nanotube as its discoverer [1, 2]. Diamond, pencil-lead, charcoal, graphite and carbon nanotube, they are made of carbon atoms, and their morphological differences result from how the carbon atoms are connected each other to form a solid、The carbon nanotube has basically the same atomic structure as graphite but it forms a nanometer-sized tube with a diameter of 1∼3 nanometer. Because of this unique morphology the carbon nanotube shows unusual electrical and mechanical properties not seen in conventional graphite. These properties make possible to build a transistor, a touch screen of smart phones, and others in electronics industry. A kind of graphene, its inventors were awarded the Nobel Prize in physics in 2010, is similar to the carbon nanotube. I found accidentally the carbon nanotube but actually its discovery was a consequence of my long experiences with high resolution electron microscopy. I was curious to see ultimate crystal structures that should be built up by atoms. So visualization of individual atoms under the microscope is an attractive subject to work with and many microscopists challenged to this goal. My effort has been rewarded in successful observation of individual atoms in the 1970 [3, 4]. Such curiosity and dedication have been connected to the discovery of carbon nanotube. My talk will also cover the latest research activities in nanocarbon materials research that have been done by modern high resolution electron microscopes.
