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news13eueuMicroscopyandAnalysis | July/August 2017above Canadian flag etched into a pennyMcMaster Universityleft Maple leaf demonstrates the technique of building structures atom by atom via STMAlberta UniversityResearchers have been busy celebrating Canada's 150th birthday by showing the world exactly what they can do in the laboratory.Research engineer, Travis Casagrande, from the Canadian Centre for Electron Microscopy at McMaster University used a focused ion beam microscope – the Zeiss NVision40 FIB – to etch a Canadian flag onto the face of a penny.Claiming to have made the world's smallest 3D Canadian flag, Casagrande first milled a tiny hole into the penny, leaving a flagpole standing within the centre.He then fabricated the maple leaf flag from the penny's surface, placing and securing it onto the flagpole with a deposited metal layer.The entire process took around six hours, and according to Casagrande, the trickiest part was forming the shape of the flag.Meanwhile, in a further tiny act of patriotism, researchers from the University of Alberta used scanning tunnelling microscopy to fabricate a maple leaf from 32 hydrogen atoms.Only ten nanometres wide, the leaf is roughly 100 times smaller than the world's smallest national flag, created at the University of Waterloo in September 2016.Researcher Roshan Achal, from the laboratory of Professor Robert Wolkow at the National Institute for Nanotechnology, patterned the leaf onto a silicon wafer using a tungsten STM tip that tapers down to the thickness of a single atom." It's super cool and super Canadian, and demonstrates our strength and skill in this niche of nanotechnology," says Achal." Almost no one else in the world can do it this well."Canada researchers celebrate 150 years with microscopyResearchers at Sweden-based Linköping University and the University of California in Berkeley, US, have observed the migration of atoms between the layers of a thin film.Using high resolution scanning transmission electron microscopy, they imaged the positions of individual atoms in the material.The specimen they studied was a thin film in which layers of a metal, hafnium nitride (HfN), around 5 nm thick, alternated with layers of a semiconductor, scandium nitride (ScN), suitable for use in microelectronics.As the researchers point out, the layers of metal and semiconductor shouldn't mix as problems arise if the atoms diffuse across an interlayer forming a closed bridge between the layers in the film, similar to an electric short circuit.To study the phenomenon, Magnus Garbrecht from the Department of Physics, Chemistry and Biology at Linköping University, heated HfN/ScN to 950°C, and noticed that the hafnium was diffusing down into the underlying layers.Further analysis revealed that a defect was present in the material where this phenomenon arose.He and colleagues heated the material several times and subsequently examined it using STEM, measuring the distance that individual atoms moved."The values we measured agree well with those from previous experiments using indirect methods and with the theoretical models, and this makes us confident that what we are seeing is dislocation-pipe diffusion," says Garbrecht.Research is published in Scientific Reports.STEM captures elusive atomic motionUsing STEM to capture diffusion in thin films Linköping Universitet