TY - CONF A1 - Heyde, M. A1 - Sturm, Heinz A1 - Rademann, K. T1 - A new application of scanning probe microscopy piezos T2 - Raster-Sonden-Mikroskopien und organische Materialien VII CY - Berlin, Germany DA - 1998-10-07 PY - 1998 AN - OPUS4-6466 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Sturm, Heinz A1 - Stark, Wolfgang A1 - Bovtun, V. A1 - Schulz, Eckhard ED - Xia, Z. T1 - Methods for simultaneous measurements of topography and local electrical properties using scanning force microscopy N2 - Two different approaches to investigate the local complex conductivity and the surface charge with Scanning Force Microscopy (SFM) techniques are presented. It is shown that the measurement of local electrical properties with SFM leads to interesting information about the composition of electrically heterogeneous surfaces T2 - 9th International Symposium on Electrets (ISE 9) CY - Shanghai, China DA - 1996-09-25 PY - 1996 SN - 0-7803-2695-4 DO - https://doi.org/10.1109/ISE.1996.578073 SP - 223 EP - 228 PB - IEEE Service Center CY - Piscataway, NJ AN - OPUS4-6851 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Sturm, Heinz A1 - Schulz, Eckhard A1 - Stark, Wolfgang A1 - Bovtun, V. A1 - Friedrich, Jörg Florian ED - Olefjord, I. ED - Nyborg, L. ED - Briggs, D. T1 - Techniques for surface composition analysis with scanning force microscopy (SFM) using electrical surface properties T2 - 7th European Conference on Applications of Surface and Interface Analysis CY - Göteborg, Sweden DA - 1997-06-16 PY - 1997 SN - 0-471-97827-2 SP - 579 EP - 582 PB - Wiley CY - Chichester AN - OPUS4-6854 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sturm, Heinz A1 - Schmittgens, Ralph T1 - SFM inside ESEM: A study of the electric properties of Polyaniline T2 - Polydays 2002 CY - Berlin, Germany DA - 2002-09-30 PY - 2002 AN - OPUS4-6538 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bovtun, V. A1 - Sturm, Heinz A1 - Leshchenko, M. A. A1 - Yakimenko, Y. T1 - Dynamics of nanodomains (clusters) and dielectric relaxation in disordered ferroelectrics KW - Lead magnoniobate KW - Phase-transition KW - Dispersion PY - 1997 SN - 0015-0193 SN - 1563-5112 VL - 190 IS - 1-4 SP - 161 EP - 166 PB - Taylor & Francis CY - New York, NY AN - OPUS4-6853 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sturm, Heinz A1 - Schulz, Eckhard T1 - Rasterkraftmikroskopie mit lokalem Leitfähigkeitskontrast zur Oberflächenanalyse von Kohlefaseroberflächen und plasmapolymerisierten dünnen Schichten PY - 1995 SN - 0340-3815 VL - 28 SP - 51 EP - 58 PB - Remy CY - Münster, Westf. AN - OPUS4-6847 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sturm, Heinz T1 - Scanning force microscopy experiments probing micromechanical properties on polymer surfaces using harmonically modulated friction techniques - I. Principles of operation N2 - Applying a high-frequency lateral vibration between the sample surface and the tip of a scanning force microscope (SFM), a harmonically modulated lateral (friction) force image can be obtained using lock-in techniques. The principles of operation are explained, in particular the dramatic decrease of image artefacts generally caused by topography cross-talk and laser beam interference. Flat interfaces between the two immiscible polymers, poly(methyl methacrylate) (PMMA) and polystyrene (PS), are prepared on a sodium chloride single crystal from the melt. These samples are used to evaluate the appropriate model for the tip-sample interaction geometry. The relationship between frictional and normal force does not follow Amonton's law. This shows that a single-asperity interaction between the tip and sample surface can be considered. Using the new technique, local measurements of shear strength and Young's modulus can be performed. KW - Atomic-scale friction KW - Nanotribology KW - Tip PY - 1999 DO - https://doi.org/10.1002/masy.19991470124 SN - 1022-1360 SN - 0258-0322 SN - 1521-3900 VL - 147 SP - 249 EP - 258 PB - Wiley-VCH Verl. CY - Weinheim, Germany AN - OPUS4-6855 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Solomun, Tihomir A1 - Sturm, Heinz T1 - Bringing electrons and microarray technology together N2 - Low-energy secondary electrons are the most abundant radiolysis species which are thought to be able to attach to and damage DNA via formation and decay of localized molecular resonances involving DNA components. In this study, we analyze the consequences of low-energy electron impact on the ability of DNA to hybridize (i.e., to form the duplex). Specifically, single-stranded thymine DNA oligomers tethered to a gold surface are irradiated with very low-energy electrons (E = 3 eV, which is below the 7.5 eV ionization threshold of DNA) and subsequently exposed to a dye-marked complementary strand to quantify by a fluorescence method the electron induced damage. The damage to (dT)25 oligomers is detected at quite low electron doses with only about 300 electrons per oligomer being sufficient to completely preclude its hybridization. In the microarray format, the method can be used for a rapid screening of the sequence dependence of the DNA-electron interaction. We also show for the first time that the DNA reactions at surfaces can be imaged by secondary electron (SE) emission with both high analytical and spatial sensitivity. The SE micrographs indicate that strand breaks induced by the electrons play a significant role in the reaction mechanism. KW - Low energy electrons KW - DNA hybridization KW - Low voltage SEM KW - Fluorescence PY - 2007 DO - https://doi.org/10.1021/jp075338v SN - 1520-6106 SN - 1089-5647 VL - 111 IS - 36 SP - 10636 EP - 10638 PB - Soc. CY - Washington, DC AN - OPUS4-15840 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chung, Jae Un A1 - Munz, Martin A1 - Sturm, Heinz T1 - Stiffness variation in the interphase of amine-cured epoxy adjacent to copper microstructures N2 - In an effort to expand the understanding of the mechanical properties of the polymeric interphase on a metal surface, a composite consisting of epoxy and copper was prepared and analyzed. Scanning force microscopy-based force modulation microscopy (SFM-FMM) was employed along with dynamic mechanical analysis (DMA) and energy dispersive X-ray analysis (EDX). Diglycidyl ether of bisphenol A (DGEBA)-based epoxy resins were applied with amine curing agents. The samples were made taking advantage of electron beam lithography (EBL) in order to produce sharp edges of copper structures and a flat surface suitable for the SFM-FMM analysis, which was able to depict the stiffness within the interphase. It is considered significant information because the mechanical characteristic within the narrow interphase was revealed. Comparing with DMA and EDX, the stiffness information of SFM-FMM demonstrated a matching correlation and agreement in terms of preferential adsorption of the curing agent in the vicinity of the interface. The stiffness profiles of the two epoxy systems turned out to be different, and it shows the material dependence of the interphase characteristics. KW - Polymer-metal KW - Interphase KW - Stiffness KW - SFM/AFM KW - DMA KW - EDX KW - Epoxy KW - Copper PY - 2007 SN - 0142-2421 SN - 1096-9918 VL - 39 IS - 7 SP - 624 EP - 633 PB - Wiley CY - Chichester AN - OPUS4-14973 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maibohm, C. A1 - Brewer, J.R. A1 - Sturm, Heinz A1 - Balzer, F. A1 - Rubahn, H.-G. T1 - Bleaching and coating of organic nanofibers N2 - Based on an analysis of the diffusive heat flow equation, we determine limits on the localization of heating of soft materials and biological tissues by electromagnetically excited nanoparticles. For heating by rf magnetic fields or heating by typical continuous wave lasers, the local temperature rise adjacent to magnetic or metallic nanoparticles is negligible. However, heat dissipation for a large number of nanoparticles dispersed in a macroscopic region of a material or tissue produces a global temperature rise that is orders of magnitude larger than the temperature rise adjacent to a single nanoparticle. One approach for producing a significant local temperature rise on nanometer length scales is heating by high-power pulsed or modulated lasers with low duty cycle. KW - Nanofibers KW - Degradation KW - Bleaching KW - Luminescence KW - Silicon monoxide KW - Diffusion barrier KW - Security labels PY - 2006 DO - https://doi.org/10.1063/1.2335783 SN - 0021-8979 SN - 1089-7550 VL - 100 SP - 054304-1 - 054304-6 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-12761 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -