Nasschemische Herstellung und Eigenschaften verlustarmer Mangan-Zink-Ferrite für Hochfrequenzanwendungen
[Online-Ausg.]. - Ilmenau : Univ.-Verl. Ilmenau, 2009. - Online-Ressource (PDF-Datei: XIV, 230 S., 34,66 MB). - (Werkstofftechnik aktuell ; 1) : Ilmenau, Techn. Univ., Diss., 2009
Enth. außerdem: Thesen
Im Zuge des Miniaturisierungstrends elektronischer Bauelemente sind höhere Arbeitsfrequenzen gefordert, wobei die Bauteile das gleiche Niveau der Energieübertragung besitzen sollen. Um diesen Anforderungen gerecht zu werden, werden neue Mangan-Zink-Ferritmaterialien mit geringer Verlustleistung bei hohen Arbeitsfrequenzen benötigt. Mangan-Zink-Ferrite sind weichmagnetische Materialien, die zur verlustarmen Leistungsübertragung, z.B. in den Schaltungsnetzteilen eingesetzt werden. Es gibt drei Beiträge zum Gesamtleistungsabfall: Hysterese- (PH), Wirbelstrom- (PE) und Restverluste (PR), wobei die beiden letztgenannten die dominierenden Verlustbeiträge bei hohen Arbeitsfrequenzen (> 500 kHz) sind. In dieser Arbeit wird das Potenzial von Mangan-Zink-Ferritnanopulvern für die Herstellung verlustleistungsarmer Ferrite erforscht. Dafür werden nanoskalige Ferritpulver mit Hilfe nasschemischer Präparationsverfahren synthetisiert. Der Einfluss von oxidischen Dotierungen und des Sinterprozesses auf die Verlustleistungseigenschaften sind ebenfalls Gegenstand der Untersuchungen dieser Arbeit.
http://nbn-resolving.de/urn:nbn:de:gbv:ilm1-2009000098
Phase transition kinetics in austempered ductile iron (ADI). - In: International foundry research, ISSN 0046-5933, Bd. 61 (2009), 2, S. 14-21
Sliding friction of nanocomposite WC1-x/C coatings: transfer film and its influence on tribology. - In: Journal of nanoscience and nanotechnology, ISSN 1533-4899, Bd. 9 (2009), 6, S. 3499-3505
http://dx.doi.org/10.1166/jnn.2009.NS23
Controlled localised melting in silicon by high dose germanium implantation and flash lamp annealing. - In: Nuclear instruments & methods in physics research. Beam interactions with materials and atoms. - Amsterdam [u.a.] : Elsevier, 1984- , ZDB-ID: 1466524-4, Bd. 267 (2009), 8/9, S. 1269-1272
http://dx.doi.org/10.1016/j.nimb.2009.01.143
Formation and characterization of NaCl-type FeC. - In: Materials letters, ISSN 1873-4979, Bd. 63 (2009), 16, S. 1445-1447
http://dx.doi.org/10.1016/j.matlet.2009.03.036
Diffusion, convection, and solidification in cw-mode free electron laser nitrided titanium. - In: Journal of applied physics, ISSN 1089-7550, Bd. 105 (2009), 8, 083503, insges. 6 S.
Titanium sheets were irradiated by free electron laser radiation in cw mode in pure nitrogen. Due to the interaction, nitrogen diffusion occurs and titanium nitride was synthesized in the tracks. Overlapping tracks have been utilized to create coatings in order to improve the tribological properties of the sheets. Caused by the local heating and the spatial dimension of the melt pool, convection effects were observed and related to the track properties. Stress, hardness, and nitrogen content were investigated with x-ray diffraction, nanoindention, and resonant nuclear reaction analysis. The measured results were correlated with the scan parameters, especially to the lateral track shift. Cross section micrographs were prepared and investigated by means of scanning electron microscopy. They show the solidification behavior, phase formation, and the nitrogen distribution. The experiments give an insight into the possibilities of materials processing using such a unique heat source.
https://doi.org/10.1063/1.3097781
Das physikalische Praktikum : Handbuch 2009 für Studentinnen und Studenten der Physik ; mit 21 Tabellen. - Göttingen : Univ.-Verl. Göttingen, 2009. - Online-Ressource (PDF-Datei: IX, 262 S., 5,7 MB). - (Universitätsdrucke)
Das Handbuch 2009 ist die "Anleitung" zum Grundpraktikum für Studentinnen und Studenten der Physik an der Georg-August-Universität Göttingen. Es beschreibt die Versuche und deren Grundlagen, die im Göttinger Physikalischen Praktikum vom zweiten bis zum vierten Semester durchzuführen sind.
https://doi.org/10.17875/gup2009-99
Nitrided amorphous stainless steel coatings deposited by reactive magnetron sputtering from an austenitic stainless steel target. - In: Advanced engineering materials, ISSN 1527-2648, Bd. 11 (2009), 1/2, S. 17-25
Stainless steel films were reactively magnetron sputtered in argon/nitrogen gas flow onto oxidized silicon wafers using austenitic AISI 316 stainless-steel targets. The deposited films of about 300 nm thickness were characterized by conversion electron Mössbauer spectroscopy, magneto-optical Kerreffect, X-ray diffraction, Rutherford backscattering spectrometry, and resonant nuclear reaction analysis. These complementary methods were used for a detailed examination of the nitriding effects for the sputtered stainless-steel films. The formation of an amorphous and soft ferromagnetic phase in a wide range of the processing parameters was found. Further, the influence of postvacuum-annealing was examined by perturbed angular correlation to achieve a comprehensive understanding of the nitriding process and phase formation. The amorphous phase is not very stable and crystallization can be observed at 973 K.
https://doi.org/10.1002/adem.200800228
Amorphous stainless steel coatings prepared by reactive magnetron-sputtering from austenitic stainless steel targets. - In: Applied physics, ISSN 1432-0630, Bd. 94 (2009), 1, S. 139-154
Stainless steel films were reactively magnetron sputtered in argon/methane gas flow onto oxidized silicon wafers using austenitic stainless-steel targets. The deposited films of about 200 nm thickness were characterized by conversion electron Mössbauer spectroscopy, magnetooptical Kerr-effect, X-ray diffraction, scanning electron microscopy, Rutherford backscattering spectrometry, atomic force microscopy, corrosion resistance tests, and Raman spectroscopy. These complementary methods were used for a detailed examination of the carburization effects in the sputtered stainless-steel films. The formation of an amorphous and soft ferromagnetic phase in a wide range of the processing parameters was found. Further, the influence of the substrate temperature and of post vacuum-annealing were examined to achieve a comprehensive understanding of the carburization process and phase formation.
http://dx.doi.org/10.1007/s00339-008-4685-x
Moderne Röntgenbeugung : Röntgendiffraktometrie für Materialwissenschaftler, Physiker und Chemiker
2., überarb. und erw. Aufl.. - Wiesbaden : Vieweg + Teubner, 2009. - XIV, 564 S.. - (Studium) ISBN 978-3-8351-0166-1
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