Jul. 24, 2014
Polarization charges in ferroelectric materials are screened by equal amounts of surface charges with opposite polarity under ambient conditions. Researchers from the Center for Nanoscale Materials, Argonne's Nanoscience & Technology and Materials Science divisions, and Tohoku University have shown that scraping, collecting, and quantifying surface screen charges reveals the underlying polarization domain structure at high speed, a technique dubbed charge gradient microscopy (CGM).
moreJun. 16, 2014
Using a newly developed nano-imaging method, LMU researchers show that thin-film organic semiconductors contain regions of structural disorder that could inhibit the transport of charge and limit the efficiency of organic electronic devices. The results have been published in Nature Communications.
moreMay. 19, 2014
High energy focused ion beam (FIB) milling produces ion-induced damage into TEM samples and a certain amount of Ga ions implantation cannot be avoided. Additional polishing of FIB lamellae at low voltages can damage the sample further. To overcome these disadvantages, a low-energy Ar+-milling of a FIB lamellae can be applied [1,2]. In this work, we focus on TEM sample preparation of different thin films and interface structures using a combination of FIB with a focused low-energy Ar+-polishing.
moreFeb. 07, 2014
When thin films of ferroelectric materials are grown on single-crystal substrates, they can develop regions of aligned polarization - called "domains" - that often adopt complex patterns. Manipulation of ferroelectric domains can lead to advances in a number of technologies. However, in order to manipulate the domains, it is important to study their natural development. Previous studies have shown that interfacial strain and electrical boundary conditions play a large role. Accurate measurements of the local polarization can help science learn more. By changing the properties of the substrate and the interfaces of the ferroelectric materials, one can control the size and shape of the domains and thus influence the behavior of the material.
moreFeb. 06, 2014
Researchers in the Department of Electrical and Computer Engineering at The University of Texas at Austin (UT ECE) have demonstrated the ability to perform nanoscale chemical analysis of molecular films with unprecedented sensitivity by detecting molecular photoexpansion. PhD students Feng Lu and Mingzhou Jin led by Prof. Mikhail Belkin successfully acquired high-quality infrared spectra from as few as 300 molecules in ambient conditions and achieved better than 25 nm spatial resolution. These capabilities enable a highly-sensitive nanoscale analytical tool for chemists, biologists and materials scientists. The results were published in Nature Photonics.
moreOct. 05, 2013
The combination of ACOM-TEM with in situ straining inside a TEM enables direct imaging of the local crystal orientation at the nanoscale during straining of nanocrystalline metals and thus various deformation processes such as grain growth, twinning/detwinning and grain rotation can be distinguished in real space. A quantitative analysis of the crystal orientation changes observed by this new approach was used to study the deformation processes in nanocrystalline gold .
moreOct. 11, 2012
The theoretical and experimental framework of a new coherent diffraction strain imaging approach was developed in the Center for Nanoscale Materials' X-Ray Microscopy Group in collaboration with Argonne's Materials Science Division, together with users from IBM.
moreSep. 27, 2012
In situ and analytical transmission electron microscopy (TEM) has been used to investigate the mechanism of material transport during Al-induced layer exchange (ALILE) and crystallization of amorphous Si (a-Si).
moreApr. 17, 2012
Scanning Electron Microscopy (SEM) has become a valuable tool for two- and three-dimensional characterization of micro- and nano-scale samples. A wide range of industry applications stand to benefit from this technology, e.g., materials research, development of pharmaceutical products, and process development in semiconductor or photovoltaic manufacturing. What they have in common: a specific region of a specimen has to be analyzed.
moreApr. 16, 2012
Electron microscopy, conducted as part of the Shared Research Equipment (ShaRE) User Program at the Department of Energy's Oak Ridge National Laboratory, has led to a new theory to explain intriguing properties in a material with potential applications in capacitors and actuators.