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Chokki J, Darracq G, Poelt P, Baron J, Gallard H, Joyeux M, Teychené B. Investigation of Poly(ethersulfone)/Polyvinylpyrrolidone ultrafiltration membrane degradation by contact with sodium hypochlorite through FTIR mapping and two-dimensional correlation spectroscopy. Polym Degrad Stab 2019. [DOI: 10.1016/j.polymdegradstab.2019.01.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Reingruber H, Zankel A, Mayrhofer C, Poelt P. A new in situ method for the characterization of membranes in a wet state in the environmental scanning electron microscope. J Memb Sci 2012. [DOI: 10.1016/j.memsci.2012.01.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Rumpf K, Granitzer P, Hilscher G, Albu M, Poelt P. Magnetically interacting low dimensional Ni-nanostructures within porous silicon. Microelectron Eng 2012; 90:83-87. [PMID: 22308049 PMCID: PMC3242907 DOI: 10.1016/j.mee.2011.05.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Electrodeposition of ferromagnetic metals, a common method to fabricate magnetic nanostructures, is used for the incorporation of Ni structures into the pores of porous silicon templates. The porous silicon is fabricated in various morphologies with average pore-diameters between 40 and 95 nm and concomitant pore-distances between 60 and 40 nm. The metal nanostructures are deposited with different geometries as spheres, ellipsoids or wires influenced by the deposition process parameters. Furthermore small Ni-particles with diameters between 3 and 6 nm can be deposited on the walls of the porous silicon template forming a metal tube. Analysis of this tube-like arrangement by transmission electron microscopy (TEM) shows that the distribution of the Ni-particles is quite narrow, which means that the distance between the particles is smaller than 10 nm. Such a close arrangement of the Ni-particles assures magnetic interactions between them. Due to their size these small Ni-particles are superparamagnetic but dipolar coupling between them results in a ferromagnetic behavior of the whole system. Thus a semiconducting/ferromagnetic hybrid material with a broad range of magnetic properties can be fabricated. Furthermore this composite is an interesting candidate for silicon based applications and the compatibility with today's process technology.
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Affiliation(s)
- K. Rumpf
- Institute of Physics, Karl Franzens University Graz, Universitaetsplatz 5, A-8010 Graz, Austria
| | - P. Granitzer
- Institute of Physics, Karl Franzens University Graz, Universitaetsplatz 5, A-8010 Graz, Austria
| | - G. Hilscher
- Institute of Solid State Physics, Vienna University of Technology, Wiedner Hauptstr. 8, 1040 Vienna, Austria
| | - M. Albu
- Institute for Electron Microscopy, University of Technology Graz, Steyrergasse 17, A-8010 Graz, Austria
| | - P. Poelt
- Institute for Electron Microscopy, University of Technology Graz, Steyrergasse 17, A-8010 Graz, Austria
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Poelt P, Zankel A, Gahleitner M, Ingolic E, Grein C. Tensile tests in the environmental scanning electron microscope (ESEM) – Part I: Polypropylene homopolymers. POLYMER 2010. [DOI: 10.1016/j.polymer.2010.04.068] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Rumpf K, Granitzer P, Albu M, Poelt P. Electrochemically Fabricated Silicon/Metal Hybrid Nanosystem with Tailored Magnetic Properties. ACTA ACUST UNITED AC 2010. [DOI: 10.1149/1.3269188] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Rumpf K, Granitzer P, Poelt P. Synthesis and Magnetic Characterization of Metal-filled Double-sided Porous Silicon Samples. Nanoscale Res Lett 2009; 5:379-382. [PMID: 20672059 PMCID: PMC2894162 DOI: 10.1007/s11671-009-9492-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Accepted: 11/02/2009] [Indexed: 05/29/2023]
Abstract
A magnetic semiconductor/metal nanocomposite with a nanostructured silicon wafer as base material and incorporated metallic nanostructures (Ni, Co, NiCo) is fabricated in two electrochemical steps. First, the silicon template is anodized in an HF-electrolyte to obtain a porous structure with oriented pores grown perpendicular to the surface. This etching procedure is carried out either in forming a sample with a single porous layer on one side or in producing a double-sided specimen with a porous layer on each side. Second, this matrix is used for deposition of transition metals as Ni, Co or an alloy of these. The achieved hybrid material with incorporated Ni- and Co-nanostructures within one sample is investigated magnetically. The obtained results are compared with the ones gained from samples containing a single metal.
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Affiliation(s)
- K Rumpf
- Institute of Physics, Karl Franzens University, Universitaetsplatz 5, 8010, Graz, Austria
| | - P Granitzer
- Institute of Physics, Karl Franzens University, Universitaetsplatz 5, 8010, Graz, Austria
| | - P Poelt
- Institute for Electron Microscopy, University of Technology, Steyrergasse 17, 8010, Graz, Austria
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Granitzer P, Rumpf K, Roca AG, Morales MP, Poelt P, Albu M. Investigation of a Mesoporous Silicon Based Ferromagnetic Nanocomposite. Nanoscale Res Lett 2009; 5:374-8. [PMID: 20672039 PMCID: PMC2894348 DOI: 10.1007/s11671-009-9491-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Accepted: 11/02/2009] [Indexed: 05/12/2023]
Abstract
A semiconductor/metal nanocomposite is composed of a porosified silicon wafer and embedded ferromagnetic nanostructures. The obtained hybrid system possesses the electronic properties of silicon together with the magnetic properties of the incorporated ferromagnetic metal. On the one hand, a transition metal is electrochemically deposited from a metal salt solution into the nanostructured silicon skeleton, on the other hand magnetic particles of a few nanometres in size, fabricated in solution, are incorporated by immersion. The electrochemically deposited nanostructures can be tuned in size, shape and their spatial distribution by the process parameters, and thus specimens with desired ferromagnetic properties can be fabricated. Using magnetite nanoparticles for infiltration into porous silicon is of interest not only because of the magnetic properties of the composite material due to the possible modification of the ferromagnetic/superparamagnetic transition but also because of the biocompatibility of the system caused by the low toxicity of both materials. Thus, it is a promising candidate for biomedical applications as drug delivery or biomedical targeting.
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Affiliation(s)
- P Granitzer
- Institute of Physics, Karl Franzens University Graz, Universitaetsplatz 5, 8010, Graz, Austria
| | - K Rumpf
- Institute of Physics, Karl Franzens University Graz, Universitaetsplatz 5, 8010, Graz, Austria
| | - AG Roca
- Instituto de Ciencia de Materiales de Madrid, CSIC, Sor Juana Ines de la Cruz 3, 28049, Cantoblanco, Madrid, Spain
| | - MP Morales
- Instituto de Ciencia de Materiales de Madrid, CSIC, Sor Juana Ines de la Cruz 3, 28049, Cantoblanco, Madrid, Spain
| | - P Poelt
- Institute for Electron Microscopy, University of Technology Graz, Steyrergasse 17, 8010, Graz, Austria
| | - M Albu
- Institute for Electron Microscopy, University of Technology Graz, Steyrergasse 17, 8010, Graz, Austria
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Granitzer P, Rumpf K, Poelt P, Albu M, Chernev B. The interior interfaces of a semiconductor/metal nanocomposite and their influence on its physical properties. ACTA ACUST UNITED AC 2009. [DOI: 10.1002/pssc.200881730] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Poelt P, Aberer W, Aberer E. Progressive circumscribed sclerosis--a novel side-effect of immunotherapy with aluminium-adsorbed allergen extracts. Allergy 2009; 64:965-7. [PMID: 19243363 DOI: 10.1111/j.1398-9995.2009.01999.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Zankel A, Poelt P, Gahleitner M, Ingolic E, Grein C. Tensile tests of polymers at low temperatures in the environmental scanning electron microscope: an improved cooling platform. Scanning 2007; 29:261-269. [PMID: 18076055 DOI: 10.1002/sca.20075] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The investigation of the fracture behavior of polymers in the environmental scanning electron microscope (ESEM) can provide information about the correlation between the microstructure of a specimen and the macroscopic stress-strain characteristic. As the mechanical properties of polymers change dramatically at the glass transition temperature, cooling of the specimens during the tensile tests can yield very valuable information about the influence of individual components of polymer blends on the fracture behavior of the material. A serious problem in this connection is the poor heat conductivity of polymers. A commercially available cooling platform, which can be mounted on the tensile stage used for the tests was substantially modified to both enhance the heat transfer between platform and specimen, and to minimize the temperature gradient along the specimen. The first experiments on modified polypropylene specimens already delivered some unexpected results. Fibril-like structures appeared at the crack tip that would not be expected at temperatures below the glass transition temperature of the polymer blend.
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Affiliation(s)
- A Zankel
- Institute for Electron Microscopy, Graz University of Technology, A-8010 Graz, Austria.
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Abstract
The dynamic recrystallization as well as meta-dynamic and static recrystallization of the nickel-based alloy 80A was investigated by means of electron backscatter diffraction (EBSD). Specimens were hot compressed at a temperature of 1120 degrees C and a strain rate of 0.1/s at varying strain and soak times to describe the recrystallization behaviour. Various approaches were tested in order to differentiate between recrystallized and deformed grains based on EBSD data. The grain orientation spread was clearly found to be the most reliable procedure. A high twinning of the recrystallized grains was observed, and as a consequence the measured grain size was strongly dependent on whether the coherent and incoherent twin boundaries were regarded as genuine boundaries or removed.
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Affiliation(s)
- S Mitsche
- Research Institute for Electron Microscopy, Graz University of Technology, Steyrergasse 17, A-8010 Graz, Austria.
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Mitsche S, Poelt P, Wagner J. Analysis of submicron particles by scanning electron microscopy-energy-dispersive X-ray spectrometry-accuracy of size measurement. Scanning 2006; 28:282-8. [PMID: 17063768 DOI: 10.1002/sca.4950280507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Scanning electron microscopy combined with energy-dispersive x-ray spectrometry (SEM-EDXS) is widely used for particle analysis. In the case of submicron particles, especially for particles that are smaller than 300 nm, the measured particle size is influenced by specimen preparation, SEM operating parameters, the mean atomic number of the particles, and the threshold value used for binarization. The use of uncoated particles on a conductive substrate and image acquisition using an in-lens detector are recommended for precise morphologic results in this size range.
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Affiliation(s)
- S Mitsche
- Graz University of Technology, Institute for Electron Microscopy, Graz, Austria.
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Wenzl FP, Suess C, Poelt P, Mauthner G, List EJW, Bouguettaya M, Reynolds JR, Leising G. The influence of the ion distribution on interfacial effects in oligoether functionalized poly(p-phenylene) based mixed ionic electronic conductors. SURF INTERFACE ANAL 2004. [DOI: 10.1002/sia.1835] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Poelt P, Schmied M, Obernberger I, Brunner T, Dahl J. Automated analysis of submicron particles by computer-controlled scanning electron microscopy. Scanning 2002; 24:92-100. [PMID: 11998907 DOI: 10.1002/sca.4950240207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Automated analysis of submicron particles by computer-controlled scanning electron microscopy is generally possible. The minimum diameter of the detectable particles is dependent on the mean atomic number of the particles and the operating parameters of the scanning microscope. The main limitation with regard to particle size is set by the quality of the particle detection system, which generally is the backscatter electron detector. The accuracy of the results of the x-ray analyses is very often strongly affected by specimen damage, omnipresent especially for environmental particles even at low electron energies and probe currents. With the exception for light elements, the detection limit is approximately 1 wt%. Device-related limitations to automated analysis may be specimen drift and an unreliable autofocus function.
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Affiliation(s)
- P Poelt
- Research Institute for Electron Microscopy, Graz University of Technology, Austria
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