Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Journal of Applied Physics
Type of Medium
Language
Year
  • 1
    Language: English
    In: Journal of Applied Physics, 01 August 2010, Vol.108(3)
    Description: We search for all equilibrium domain-wall solutions in finite-size magnetic composite media. We find that the critical fields and the reversal mechanism are determined by the structure of these solutions. The domain-wall propagation field retains its infinite-length value as long as the soft-phase wall solution E 1 remains a complete wall. As soft-phase length l 1 is reduced below the hard-phase domain-wall width ε 2 , soft wall solution E 1 loses its wall structure or vanishes abruptly. Consequently, reversal by wall propagation is not possible or becomes indistinguishable from nucleation. We also find that the finite system size introduces a new unstable surface solution E s . This is in addition to the unstable hard-phase wall solution E 2 , and the stable soft-phase wall solution E 1 which were present in the infinite system. The nucleation field H n and reversal by nucleation are shown to be related to E s . Finally, energy landscapes are described where the energy barriers and energy well are determined from wall energies and wall spatial locations. The vanishing of the barriers corresponds to the critical fields. The predictions of the calculations are compared with experiment.
    Keywords: Articles
    ISSN: 0021-8979
    E-ISSN: 1089-7550
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: Journal of Applied Physics, 01 January 2012, Vol.111(1)
    Description: We propose a novel method to image spin properties of spintronic systems using the spatially confined field of a scanned micromagnetic probe in conjunction with existing electrical or optical global spin detection schemes. It is thus applicable to all material systems susceptible to either of those approaches. The proposed technique relies on numerical solutions of the spin diffusion equation in the presence of spatially varying fields to obtain the local spin response to a micromagnetic probe field.
    Keywords: Articles
    ISSN: 0021-8979
    E-ISSN: 1089-7550
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: Journal of Applied Physics, 15 December 2010, Vol.108(12)
    Description: The analytical Gaussian electron pulse propagation model of Michalik and Sipe [ J. Appl. Phys. 99 , 054908 ( 2006 )] is extended to include the action of external forces on the pulse. The resultant ability to simulate efficiently the effect of electron optical elements (e.g., magnetic lenses and radio-frequency cavities) allows for the rapid assessment of electron pulse delivery systems in time-resolved ultrafast electron diffraction and microscopy experiments.
    Keywords: Articles
    ISSN: 0021-8979
    E-ISSN: 1089-7550
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: Journal of Applied Physics, 21 April 2013, Vol.113(15)
    Description: We obtain angular-resolved quantitative magneto-optical measurements with good signal-to-noise ratio from very diffusive reflection patterns of industrial steel samples, which are a consequence of their large surface roughness. For the diffuse spots generated by these samples, we observe that while the overall shape of the magnetic hysteresis loop is nearly independent, a monotonous increase of the magneto-optical polarization change occurs as a function of the scattering angle. We demonstrate that this observation can be explained by considering the diffuse spot as a superposition of independent reflections from planar surfaces with varying incidence angles. This main finding can be ultimately used to facilitate an efficient non-invasive analysis of industrial magnetic samples by means of magneto-optical methods despite their elevated level of roughness.
    Keywords: Articles
    ISSN: 0021-8979
    E-ISSN: 1089-7550
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: Journal of Applied Physics, 15 July 2012, Vol.112(2)
    Description: The surface of a titanium alloy (Ti6Al4V) implant material was covered with a bioactive calcium alkali phosphate ceramic with the aim to accelerate the healing and to form a stronger bond to living bone tissue. To fix the ceramic powder we used a femtosecond laser, which causes a thin surface melting of the metal. It is a requirement to prove that the laser irradiation would not reduce the lifetime of implants. Here we present the results of mechanical stability tests, determined by the rotating bending fatigue strength of sample rods. After describing the sample surfaces and their modifications caused by the laser treatment we give evidence for an unchanged mechanical stability. This applies not only to the ceramic fixation but also to a comparatively strong laser ablation.
    Keywords: Articles
    ISSN: 0021-8979
    E-ISSN: 1089-7550
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Language: English
    In: Journal of Applied Physics, 15 May 2012, Vol.111(10)
    Description: We present an experimental and theoretical study of the reliability of generalized magneto-optical ellipsometry measurements, investigate its dependence from data set acquisition geometries, as well as investigate the underlying physics of light reflection for magneto-optical materials to explain the observed behavior. Specifically, we compare the use of two different grids of data points and evaluate their reliability and repeatability in a comparative study. We find that the conventionally used square grid is actually not ideal for generalized magneto-optical ellipsometry (GME) measurements and that the also investigated diagonal lattice is clearly superior. These experimental results were reproduced in theoretical calculations of the detection process. The physical origin of this behavior was identified to be related to the “quality” of the individual data points that are included in the data analysis process, with the highest quality data being achieved near the crossed polarizer line, i.e., the region that is more prominently utilized in the diagonal grid approach presented here. These results will help to improve the precision and the data acquisition time of GME measurements.
    Keywords: Articles
    ISSN: 0021-8979
    E-ISSN: 1089-7550
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Language: English
    In: Proceedings Of The 55th Annual Conference On Magnetism And Magnetic Materials, Atlanta, Georgia (14-18 November 2010):
    In: Journal of Applied Physics, 01 April 2012, Vol.111(7)
    Description: The magnetization reversal process of interacting elongated nanoislands is presented here. The magnetization reversal has been investigated by means of magneto-optical Kerr effect magnetometry, analyzing the beams reflected and diffracted by the array, magnetic force microscopy, and micromagnetic simulations. The nanoislands have an aspect ratio of 4.2 and are arranged in chiral square units forming a checkerboard array. Due to this particular arrangement, each island is subjected to a spatially asymmetric dipolar interaction field. We found that for certain directions of the applied field this specific character of the dipolar interaction affects the reversal process profoundly. In these cases the magnetization reversal takes places via the nucleation and displacement of a vortex state in two of the four nanoislands in every square unit, at variance with single domain rotation process generally observed for other directions of the applied field.
    Keywords: Proceedings Of The 56th Annual Conference On Magnetism And Magnetic Materials
    ISSN: 0021-8979
    E-ISSN: 1089-7550
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Language: English
    In: Journal of Applied Physics, 15 August 2012, Vol.112(4)
    Description: We employed Raman spectroscopy to investigate how the hydrostatic pressure affects the temperature of the Verwey transition in pure (Fe 3 O 4 ) and Al-doped (Fe 2.8 Al 0.2 O 4 ) magnetite. In both samples, pressure suppresses the transition. The Al-doped sample displays no transition above 8 GPa. We do not observe such discontinuity in a pure magnetite, which suggests that the discontinuity is doping driven. Our Clausius-Clapeyron formula based analysis of the pressure–transition temperature dependence is in excellent agreement with our data in pure magnetite. The Al doping leads to a smaller entropy change and larger volume expansion consistent with partial charge ordering at the transition.
    Keywords: Articles
    ISSN: 0021-8979
    E-ISSN: 1089-7550
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Language: English
    In: 11th Joint Mmm-Intermag Conference, Washington, DC (USA) (18?22 January 2010):
    In: Journal of Applied Physics, 01 May 2010, Vol.107(9)
    Description: Local-probe weak-transverse-field and zero-field μ SR measurements have been employed to investigate magnetic ordering in the new magnetoelectric compound FeTe 2 O 5 Br . Below the Néel transition temperature T N = 10.6   K a static local magnetic field starts to develop at the μ + sites. Fast μ + polarization decay below T N speaks in favor of a broad distribution of internal magnetic fields, in agreement with the incommensurate magnetic structure suggested by neutron diffraction experiments. Above T N the presence of short-range order is detected as high as at 2 T N , which suggests only weak interlayer magnetic coupling. On the other hand, strong Fe 3 + spin fluctuations likely reflect geometrically frustrated structure of [ Fe 4 O 16 ] 20 − spin clusters, which are the main building blocks of the layered FeTe 2 O 5 Br structure.
    Keywords: Proceedings Of The 11th Joint Mmm-Intermag Conference, Washington, DC, 2010
    ISSN: 0021-8979
    E-ISSN: 1089-7550
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Language: English
    In: Journal of Applied Physics, 01 July 2011, Vol.110(1)
    Description: In terahertz quantum well infrared photodetectors, a built-in-charge-mediated regime transition of the electronic transport is thoroughly investigated. The very strong current discontinuity and negative differential resistivity behavior are explained in terms of band structure reorganizations. The analysis of bias versus current measurements reveals that the transition occurs when the first two wells of the structure become partially drained, and the second well enters the ionized regime before the first one. Both many-body effects and a careful model of the contact have to be considered to account for these features. The source of the built-in charge is identified as intersubband impact ionization. The regime transition is one of its few experimental proofs, and provides an original approach to investigate hot electron kinetics in multi-quantum-well structures.
    Keywords: Articles
    ISSN: 0021-8979
    E-ISSN: 1089-7550
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages