Search Results - (Author, Cooperation:D. Dimitrov)
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1Latest Papers from Table of Contents or Articles in PressD Dimitrov, E Uheida, G Oosthuizen, D Blaine, R Laubscher, A Sterzing, P Blau, W Gerber and O F R A Damm
Institute of Physics (IOP)
Published 2018Staff ViewPublication Date: 2018-10-03Publisher: Institute of Physics (IOP)Print ISSN: 1757-8981Electronic ISSN: 1757-899XTopics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPublished by: -
2Latest Papers from Table of Contents or Articles in PressStaff View
Publication Date: 2018-07-24Publisher: Institute of Physics (IOP)Print ISSN: 1755-1307Electronic ISSN: 1755-1315Topics: GeographyGeosciencesPhysicsPublished by: -
3Latest Papers from Table of Contents or Articles in PressB. G. Holt ; J. P. Lessard ; M. K. Borregaard ; S. A. Fritz ; M. B. Araujo ; D. Dimitrov ; P. H. Fabre ; C. H. Graham ; G. R. Graves ; K. A. Jonsson ; D. Nogues-Bravo ; Z. Wang ; R. J. Whittaker ; J. Fjeldsa ; C. Rahbek
American Association for the Advancement of Science (AAAS)
Published 2013Staff ViewPublication Date: 2013-07-28Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsKeywords: Animals ; *Climate ; *PhylogenyPublished by: -
4Latest Papers from Table of Contents or Articles in PressB. G. Holt ; J. P. Lessard ; M. K. Borregaard ; S. A. Fritz ; M. B. Araujo ; D. Dimitrov ; P. H. Fabre ; C. H. Graham ; G. R. Graves ; K. A. Jonsson ; D. Nogues-Bravo ; Z. Wang ; R. J. Whittaker ; J. Fjeldsa ; C. Rahbek
American Association for the Advancement of Science (AAAS)
Published 2012Staff ViewPublication Date: 2012-12-22Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsKeywords: Amphibians/classification ; Animals ; Birds/classification ; *Climate ; Mammals/classification ; *Phylogeny ; PhylogeographyPublished by: -
5Articles: DFG German National LicensesStaff View
ISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: The nucleation field in a synthetic antiferromagnet has been studied as a function of the stabilization strength. The results can be used to predict the magnetic stability in a GMR read-back head, that utilizes a synthetic antiferromagnet instead of a single pinned layer. Experimental studies showed substantially improved magnetic stability at higher temperature in synthetic antiferromagnet spin valves. © 2000 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesDimitrov, D. V. ; Unruh, K. ; Hadjipanayis, G. C.
[S.l.] : American Institute of Physics (AIP)
Published 2000Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: Ferrimagnetic properties, large saturation magnetization (Ms) and low temperature coercivity (Hc) was observed in nonstoichiometric Fe1−xO films. This unusual behavior was attributed to the existence of spinel type defect clusters coherently embedded in the FeO matrix. A model, which explains the Fe1−xO properties and predicts a linear dependence between Ms and the Fe1−xO lattice parameter a with the Fe3O4 data falling on the same line, is proposed. The experimental Ms vs a curve is in excellent agreement with the theoretical prediction, which indicates the existence of a fundamental relation between FeO, Fe1−xO, and Fe3O4. © 2000 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesLi, Y. F. ; Yu, R. H. ; Dimitrov, D. V. ; Xiao, John Q.
[S.l.] : American Institute of Physics (AIP)
Published 1999Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: Temperature behavior and memory effect in standard spin valves (SV) and SVs with synthetic antiferromagnetic (Co/Ru/Co) (SV-SAF) subsystems have been studied. SV-SAFs show much better temperature stability. Memory effect refers to the phenomenon that the exchange bias can be altered at temperatures (TR's) much lower than the blocking temperature (TB), and these temperatures (TR's) are imprinted into SVs. The memory effect greatly deteriorates the magnetoresistance behaviors in SV. Our results suggest that the memory effect is caused by a distribution of local blocking temperatures (Tb's). The magnetization state in the pinned layer is critical in determining the temperature behavior of HE and magnetoresistance. By partially reversing the magnetization in the pinned ferromagnetic (FM) layers, we are able to separate the temperature dependencies of the local exchange bias (He) associated with regions consisting of different Tb's. Two features have been observed: (1) the local exchange bias (He) with a narrow Tb distribution has a weak temperature dependence; (2) the simple algebraic sum of local He's nearly reproduce the total HE with the difference between these two quantities representing the domain wall energy in the FM layer. On the other hand, SV-SAFs show strong resistance to memory effects because of two factors; the strong exchange coupling through the Ru layer, and the net magnetic moment of Co/Ru/Co layers in SV-SAF being close to zero. The former makes the two SV-SAF FM layers behave coherently, while the latter makes the interaction between the SV-SAF and the external field negligibly small. © 1999 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesDimitrov, D. V. ; Murthy, A. S. ; Hadjipanayis, G. C. ; Swann, C. P.
[S.l.] : American Institute of Physics (AIP)
Published 1996Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: The magnetic, structural and microstructural properties of sputtered Fe thin films and Fe(backward-slash)Fe–O bilayers were studied as a function of the Fe layer thickness, the type of the Fe oxide and the substrate used. Two different ways to prepare the oxide layers were used; postdeposition oxidation and reactive sputtering. Postdeposition oxidation produced films with mixed Fe–oxides (FeO, Fe3O4, Fe2O3); however reactive sputtering led to bilayers with controlled stoichiometry, Fe(backward-slash)FeO, Fe(backward-slash)Fe3O4, and Fe(backward-slash)FE2O3, respectively. The coercivity of both the Fe films and fE(backward-slash)Fe–O bilayers, deposited on substrates with or without Cr buffer layer, was found to increase with decreasing Fe film thickness. The coercivity of the samples deposited on a Ag buffer layer was much lower and did not change substantially with the Fe film thickness. The presence of the Fe–oxide layer led to a large increase of coercivity. This is attributed to the higher anisotropy of the oxide and to exchange coupling of Fe–oxide with the softer Fe layer. © 1996 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesTsoukatos, A. ; Dimitrov, D. V. ; Murthy, A. S. ; Hadjipanayis, G. C.
[S.l.] : American Institute of Physics (AIP)
Published 1994Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: The structural and magnetotransport properties of (FeyCo1−y)100−xAgx films were studied as a function of composition. Giant magnetoresistance (GMR) values were measured in these granular films, with the best GMR obtained for the composition (Fe0.33Co0.67)27Ag73, with values of 29% at 30 K and 11.7% at 300 K. XRD and TEM results have shown a fcc crystal structure with a relatively homogeneous microstructure. Magnetic data for the samples with the best GMR indicate a superparamagnetic behavior. The narrow peak in thermomagnetic data and low blocking temperature suggest a small and uniform size distribution of magnetic granules. A summary of the electrical transport properties is presented, in relation to the structural, microstructural, and magnetic properties.Type of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesLiu, J. F. ; Zhang, Y. ; Dimitrov, D. ; Hadjipanayis, G. C.
[S.l.] : American Institute of Physics (AIP)
Published 1999Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: The effect of ratio z on the high temperature magnetic properties of Sm(Co, Fe, Cu, Zr)z magnets have been examined in a range of ratio z values from 6.7 to 9.1. Reasonably high coercivity at room temperature has been achieved in all the magnets. It was found that the lower the ratio z, the smaller the temperature coefficient of coercivity. When the ratio z=7.0, a temperature coefficient of coercivity of −0.03%/°C can be achieved, which is more than eight times smaller than the magnet with z=8.5. A coercivity of more than 10 kOe has been obtained at 773 K for the newly developed magnets, which is believed to be the highest coercivity at 773 K ever reported. Transmission electron microscope studies showed that the cell size decreases with the decrease of the ratio z, while the density of lamella phase remains almost the same. This suggests that smaller cell size leads to a smaller temperature coefficient of intrinsic coercivity. © 1999 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
11Articles: DFG German National LicensesStaff View
ISSN: 0020-711XSource: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: BiologyChemistry and PharmacologyType of Medium: Electronic ResourceURL: -
12Articles: DFG German National LicensesStaff View
ISSN: 0020-0891Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: -
13Articles: DFG German National LicensesStaff View
ISSN: 0038-1101Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: Electrical Engineering, Measurement and Control TechnologyPhysicsType of Medium: Electronic ResourceURL: -
14Articles: DFG German National LicensesStaff View
ISSN: 0038-1101Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: Electrical Engineering, Measurement and Control TechnologyPhysicsType of Medium: Electronic ResourceURL: -
15Articles: DFG German National LicensesStaff View
ISSN: 0038-1101Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: Electrical Engineering, Measurement and Control TechnologyPhysicsType of Medium: Electronic ResourceURL: -
16Articles: DFG German National LicensesStaff View
ISSN: 0038-1101Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: Electrical Engineering, Measurement and Control TechnologyPhysicsType of Medium: Electronic ResourceURL: -
17Articles: DFG German National LicensesStaff View
ISSN: 0038-1101Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: Electrical Engineering, Measurement and Control TechnologyPhysicsType of Medium: Electronic ResourceURL: -
18Articles: DFG German National LicensesStaff View
ISSN: 0006-291XSource: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: BiologyChemistry and PharmacologyPhysicsType of Medium: Electronic ResourceURL: -
19Articles: DFG German National LicensesTerman, B.I. ; Dougher-Vermazen, M. ; Carrion, M.E. ; Dimitrov, D. ; Armellino, D.C. ; Gospodarowicz, D. ; Bohlen, P.
Amsterdam : ElsevierStaff ViewISSN: 0006-291XSource: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: BiologyChemistry and PharmacologyPhysicsType of Medium: Electronic ResourceURL: -
20Articles: DFG German National LicensesStaff View
ISSN: 1435-1536Source: Springer Online Journal Archives 1860-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsDescription / Table of Contents: Zusammenfassung Der Einfluß der Oberflächenviskosität auf die Verdünnungsgeschwindigkeit und die kritische Zerreißdicke von Schaumfilmen wird untersucht. Es zeigt sich, daß dieser Effekt stark von der charakteristischen Flußgröße abhängt. Folglich kann man bei der Berechnung der Verdünnungsgeschwindigkeit die Oberflächenviskosität unberücksichtigt lassen und sie bei der von den thermischen Fluktuationen verursachten wellenartigen Bewegung als unendlich groß annehmen. Die auf diese Art erhaltenen Gleichungen für die kritische Dicke stimmen verhältnismäßig gut mit den experimentellen Daten überein. Eine mögliche Erklärung der Abhängigkeit der kritischen Dicke von der Konzentration des Tensids wird vorgeschlagen.Notes: Summary The influence of surface viscosity on the rate of thinning and on the critical thickness of rupture of foam films has been studied. It is shown that this effect depends strongly on the length-scale of the flow. Therefore it is possible to neglect it when calculating the rate of thinning, but to assume for the wave motion, caused by the thermic fluctuations, that the surface viscosity is infinitely great. The expression for the critical thickness, obtained in this way, agrees relatively well with the experimental results. A possible explanation of the dependence of critical thickness on surfactant concentration is suggested.Type of Medium: Electronic ResourceURL: