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Magnetic Force Microscopy (magnetic + force_microscopy)

Distribution by Scientific Domains

Polymers and Materials Science	37%

Selected Abstracts

Magnetic Force Microscopy in the GHz Regime

IMAGING & MICROSCOPY (ELECTRONIC), Issue 3 2007
A Study of the Magnetic Contrast from Hard Disk Writer Poles
Scanning force microscopy has become in the last two decades the most widely applied method within the field of scanning probe microscopy. In certain cases atomic resolution can be obtained and a lot of specialised modes of application allow the local detection of a variety of probe-sample-interactions. This opens the possibility to analyse physical, chemical and even biological phenomena with an unprecedented sensitivity and resolution. [source]

Magnetic force microscopy of iron oxide nanoparticles and their cellular uptake

BIOTECHNOLOGY PROGRESS, Issue 4 2009
Yu Zhang
Abstract Magnetic force microscopy has the capability to detect magnetic domains from a close distance, which can provide the magnetic force gradient image of the scanned samples and also simultaneously obtain atomic force microscope (AFM) topography image as well as AFM phase image. In this work, we demonstrate the use of magnetic force microscopy together with AFM topography and phase imaging for the characterization of magnetic iron oxide nanoparticles and their cellular uptake behavior with the MCF7 carcinoma breast epithelial cells. This method can provide useful information such as the magnetic responses of nanoparticles, nanoparticle spatial localization, cell morphology, and cell surface domains at the same time for better understanding magnetic nanoparticle-cell interaction. It would help to design magnetic-related new imaging, diagnostic and therapeutic methods. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source]

Synthesis and Characterization of Iron Oxide Derivatized Mutant Cowpea Mosaic Virus Hybrid Nanoparticles,

ADVANCED MATERIALS, Issue 24 2008
Alfredo A. Martinez-Morales
A novel nanoparticle hybrid is attained by the covalent attachment of iron oxide (, -Fe2O3) nanoclusters onto the surface of a mutagenized cow pea mosaic virus (CPMV-T184C). Using a stepwise substrate-based integration, monodisperse CPMV-IO hybrids are anchored on a gold substrate. The physical and magnetic properties of individual CPMV-IO hybrids are qualitatively investigated by atomic/magnetic force microscopy (AFM/ MFM). During MFM characterization a ,boundary-effect' is observed at the CPMV/IO interface. [source]

Ferromagnetic Spots in Graphite Produced by Proton Irradiation,

ADVANCED MATERIALS, Issue 20 2003
K.-h. Han
A proton microbeam produces ferromagnetic spots on a highly oriented graphite surface. The Figure shows the topography and the magnetic force microscopy (MFM) images obtained after irradiating the surface with a beam size of 1,,m,×,1 ,m and a dose of 0.098 nC,,m,2. The strength of the magnetic signal is only a factor of ,,10 smaller than that obtained on Fe particles. [source]

Microparticles of poly(methacrylic acid),gadolinium ion complex and their magnetic force microscopic images

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 8 2004
Tsuyoshi Michinobu
Abstract Modified poly(methacrylic acid) microparticles complexed with gadolinium(III) (Gd3+) ions were prepared in 100 nm. The emulsion terpolymerization of methacrylic acid, ethyl acrylate, and allyl methacrylate and the following complexation with Gd3+ ions yielded the polymer particles with different Gd3+ ion contents. Potentiometric titration of the complexation of the particle with Gd3+ ions indicated the formation of a very stable tris-carboxylate coordinate complex with the Gd3+ ion. Electron spin resonance and IR spectra of the complexed particles were dependent on the Gd3+ ion content and the coordination environment in each particle. The microparticles dispersed on a mica substrate were subjected to atomic force microscopy (AFM), followed by magnetic force microscopy (MFM). AFM showed 100-nm-sized and monodispersed spherical images. The following MFM clearly provided strong magnetic responses exactly on the same particle positions, of which the images were also dependent on the Gd3+ ion content in the particle. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1912,1918, 2004 [source]

Self-organization and finite size effects in epitaxial ferromagnetic MnAs films on GaAs

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 8 2007
L. Däweritz
Abstract The self-organized striped structure of coexisting ,-MnAs and ,-MnAs, characteristic for MnAs films grown on GaAs(001) by molecular beam epitaxy under As-rich conditions at low temperature, has been studied in samples prepared under conditions closer to the equilibrium. Whereas the period of the stripe pattern is independent on the preparation procedure, the width of the ferromagnetic ,-MnAs stripes increases. Thus, the aspect ratio p between the stripe width L and the stripe thickness t can be varied over a wide range. The magnetic properties of the finite-size magnetic system are investigated as a function of the ratio p at room temperature. The transition from type-I domains with meander-like contrast in the magnetic force microscopy (MFM) image to type-II domains with a line-shaped contrast due to the division of the stripe into N subdomains across the stripe occurs at p ratios expected from a model based on the shape anisotropy. Besides the well-known N = 3 type-II domains also type-II domains with N = 4, 5 were detected. When the stripe width approaches the period of the self-organized structure, the boundary between two neighboring stripes is imaged as chessboard-like contrast in the MFM pattern. The shape of the magnetic hysteresis loops changes with the p ratio or, in other words, with the predominance of in-plane or out-of plane magnetic moments in the demagnetized state. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]