Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    New perspective on the Green's function dipole-exchange spin wave theory for thin films (abstract) : 38th Annual Conference on Magnetism and Magnetic Materials (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 6084-6084 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In contrast with the scalar potential theory for dipole-exchange spin waves in thin films, the Green's function (GF) approach in combination with perturbation methods (PM) gives simple closed form dispersion equations, analytical expressions for the dipole-exchange frequency gaps, and good intuitive physics. However, in the case of in-plane magnetized films and perpendicular propagation, the GF/PM results present two major problems. (1) The multibranch dipole-exchange solutions bear little resemblance to the single dispersion curve for the well-established Damon–Eshbach magnetostatic surface modes and the nonreciprocal mode profiles predicted by the simple theory and observed experimentally. (2) The lowest order exchange branch has a curvature that is much greater than expected from either simple spin wave considerations or scalar potential theory. To resolve these problems, a simple method has been developed to solve the coupled mode equations obtained from the GF formalism without recourse to perturbation methods. The coupled mode dispersion relations obtained with this method are valid for an arbitrary field configuration and propagation direction, and are not subject to the restrictions imposed by perturbation methods. The solutions agree well with the surface mode theory for in-plane magnetized films. Good agreement is also found with the Brillouin light scattering data for iron thin films.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.355465
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    High field effective linewidth and eddy current losses in moderate conductivity single crystal Zn-Y hexagonal ferrite at 10–35 GHz (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 432-442 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The microwave losses associated with the extreme high field tail region of the ferromagnetic resonance (FMR) absorption curve for 0.08- to 1.38-mm-thick c-plane circular disks of single crystal Zn-Y hexagonal ferrite materials with planar anisotropy were investigated at 10, 19.3, and 35.3 GHz, with the static external magnetic field applied in plane. Analysis of the data in terms of magnetic losses only gave anomalous high field effective linewidth ΔHF results; this ΔHF showed a substantial increase with the field, changed with both disk thickness and radius, and was higher for an out-of-plane microwave field direction than for an in-plane direction. This linewidth did scale with the square of the disk thickness, one indication of predominant eddy current losses. The data were then analyzed in terms of eddy current losses, based on the assumption of an insulator FMR response and a high field eddy current loss absorption tail driven by that response. The predictions of the model were in good agreement with the data. Fits to the data gave reasonable and consistent values of the microwave conductivity which ranged from 0.03 to 0.05 Ω−1 cm−1 at 10 GHz to 0.06–0.07 Ω−1 cm−1 at 35 GHz, relative to a measured dc conductivity of 0.02–0.03 Ω−1 cm−1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.357093
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Magnetostatic wave dynamic magnetization response in yttrium iron garnet films (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 1595-1603 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The dynamic microwave magnetization (DMM) amplitude of magnetostatic waves in yttrium iron garnet films at 5–6 GHz has been measured as a function of input power. The measurement is based on the characteristic frequency shift in the power transmission spectrum. This shift is related to the reduction of the effective static magnetization and, therefore, the increase of the DMM amplitude at high power. The measurements were made on 7.2-μm-thick, single-crystal yttrium iron garnet films. A pulsed frequency-swept microwave signal at 5–6 GHz was used to launch the magnetostatic waves. The signals were excited and detected by planar microstrip transducers. Measurements were made for magnetostatic forward volume waves (MSFVW) and magnetostatic surface waves (MSSW). The duty cycle of the pulsed microwave signal was kept at 0.1% in order to avoid sample heating effects. The shifts for small features in the transmission vs frequency profiles were used to determine the DMM amplitudes. At low power, the DMM amplitude increased with power. Saturation occurred at high power. The results indicate a saturation DMM response at about 10% of the saturation magnetization for input power in the 3–4 W range for MSFVW signals and above 0.5 W for MSSW signals. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.361003
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Forward volume wave microwave envelope solitons in yttrium iron garnet films: Propagation, decay, and collision (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 4274-4289 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Magnetostatic forward volume wave (FVW) microwave magnetic envelope solitons in 7.2 μm thick, single-crystal yttrium iron garnet films have been studied at 5.6–6.0 GHz. Rectangular input pulses with peak powers up to 3 W and pulse widths 5–50 ns were used. Single soliton output pulses with a characteristic increase in amplitude and pulse narrowing are observed when the power or width of the rectangular input microwave pulse exceeds threshold levels. Above these levels, output pulse peak power versus input power or pulse width exhibits a nonlinear increase and shows saturation effects. Multiple peak output profiles are observed for pulse powers and widths well above threshold. Solitons could be formed for all frequencies within the usable, low transmission loss portion of the magnetostatic FVW band. The use of reflected pulses from the film edge made it possible to study soliton decay and soliton collisions. The soliton decay rate was found to be approximately twice the linear rate, as expected from theory. The collision of solitons was found to occur with no significant change in shape and velocity. The various characteristic times from theory for pulse decay, pulse dispersion, nonlinear response, and propagation are found to be consistent with the experimental results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.357312
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Frequency and temperature dependence of the ferromagnetic resonance linewidth in single crystal platelets and pulsed laser deposited films of barium ferrite (2002)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 91 (2002), S. 4426-4431 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The half power ferromagnetic resonance (FMR) linewidth ΔH has been measured from 8 to 300 K for a nominal frequency of 61 GHz and from 50 to 75 GHz at room temperature for normally magnetized single crystal platelets and pulsed laser deposited (PLD) films of barium ferrite. The platelet linewidth versus temperature data show a peak value of 27 Oe at 25–30 K, a dip to 21 Oe at 75 K, structure related to line merging at 130–160 K, and a region of slow increase at 240–295 K. The 240 –300 K data extrapolate to a 0 K linewidth of about 8 Oe. The corresponding film data show a peak value of 240 Oe at 20 K and a gradual decrease at higher temperatures. Both the platelet and film linewidths show a weak frequency dependence at about 0.3 Oe/GHz at room temperature (RT). The film data also show several linewidth spikes due to interference effects between the FMR response and dielectric resonances in the substrate. The RT linewidth zero frequency intercepts for the platelet and the film were 9 and 30 Oe, respectively. The frequency dependence of the platelet linewidth was also examined at 230–295 K. The frequency responses and intercepts for these data were affected by the line merging at lower temperatures and showed high temperature limit values of 0.35 Oe/GHz and 9.5 Oe, respectively. The linewidth frequency response in both cases is attributed to conductivity. The linewidth versus temperature peaks are attributed to impurities. The linewidth dip at 75 K for the platelet results from the drop in ΔH on the tail of the temperature peak and an increase associated with iron ion hopping motion. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1450057
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Suppression of microwave magnetic envelope solitons by continuous wave magnetostatic wave signals (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 4232-4235 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The influence of continuous wave (cw) magnetostatic wave signals on microwave magnetic envelope soliton pulse formation and propagation in magnetic films has been examined. Pulsed and cw microwave signals were applied to the input of a single crystal yttrium–iron–garnet film magnetostatic wave delay line. The nominal operating frequency was 4.8 GHz. The pulse signals served to form solitons with no cw power present. Under suitable conditions, the cw signal served to inhibit or eliminate the soliton formation and propagation. The suppression effect was measured as a function of the cw signal frequency and power. The suppression is maximized when the cw signal frequency coincides with the pulse carrier frequency. At this frequency, an input cw power of 80 mW is sufficient to suppress completely a soliton pulse formed from a 10 ns wide, 500 mW peak power input pulse. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1308099
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Modeling of microwave magnetic envelope solitons in thin ferrite films through the nonlinear Schrödinger equation (1998)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 84 (1998), S. 3776-3785 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A theoretical analysis of microwave magnetic envelope soliton profiles and the soliton peak power response for high power magnetostatic wave (MSW) excitations in yttrium iron garnet (YIG) thin films has been made. This analysis was based on the standard nonlinear Schrödinger equation with all key parameters based on experiment. The measurements were done for magnetostatic backward volume waves in a 10.2 μm YIG film, with a band edge at 5.06–5.07 GHz and operating point frequencies from 4.80 to 5.00 GHz. The use of accurate dispersion and group velocity parameters and the transmitted power versus frequency response of the MSW signal was critical. It was possible to accurately model both the shapes of the soliton pulses and the peak output versus peak input power response over a wide range of power levels. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.368556
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Spin wave instability in single crystal Zn–Y hexagonal ferrite at 8.93 GHz (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 4454-4469 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Resonance saturation (RS), subsidiary absorption (SA), and parallel pump (PP) spin wave instability threshold measurements have been made on single crystal easy plane disks of Mn substituted Zn–Y type hexagonal ferrite materials at 8.93 GHz and room temperature. For each configuration, "butterfly curves" of the spin wave instability threshold microwave field amplitude hcrit as a function of the static field applied in the disk plane were obtained. The previous theory for these instability processes was also extended to include planar magnetocrystalline anisotropy and a wave vector k dependent spin wave linewidth, ΔHk. The RS butterfly curve had a characteristic "V" shape with a rounded minimum at the ferromagnetic resonance (FMR) field. The nominal ΔHk needed to fit the data at the ferromagnetic resonance field was 7 Oe, but the butterfly curve shape indicated a k-dependent ΔHk. The butterfly curves for the PP configuration were flat at low field and then diverged rapidly at the cutoff field for first order instability processes, Hcut. The SA butterfly curves were also flat over the field interval for first order processes, but then decreased as the field was increased above Hcut. This decrease is attributed to the onset of second order processes due to the proximity of the FMR and additional magnetostatic mode peaks as one moves to and then above Hcut. The flat portions of the PP and SA butterfly curves could be fitted with a single k-independent ΔHk value of 18 Oe. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1352689
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    High-field effective linewidth and eddy current losses in moderate conductivity single-crystal M-type barium hexagonal ferrite disks at 10–60 GHz (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 2705-2718 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The losses associated with the high-field tail region of the ferromagnetic resonance (FMR) absorption curve were investigated at 10, 19, 35, and 60 GHz for 0.10–1.75-mm-thick c-plane circular disks of flux-grown single-crystal M-type barium ferrite materials. A conventional high-field effective linewidth analysis of the data yielded an effective linewidth which increased with the square of the disk thickness and linearly with frequency, dependencies which indicate a predominant eddy current loss process. Based on these results, an eddy current loss analysis of the tail region was done, based on the insulator FMR response and eddy current losses driven by the FMR response. This analysis leads to a new noninvasive technique for the determination of the microwave conductivity in moderate conductivity ferrites. One obtains the conductivity from an appropriate analysis of the FMR absorption tail in the same way that analysis of the magnetic loss tail yields a high-field effective linewidth. Based on this technique, the microwave conductivity of these flux-grown barium ferrite single-crystal materials was determined as a function of frequency and found to increase linearly from 0.033±0.004 Ω−1 cm−1 at 10 GHz to 0.10±0.02 Ω−1 cm−1 at 60 GHz. These results are consistent with a measured dc conductivity of 0.03–0.05 Ω−1 cm−1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.354665
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    First-order instability theory for magnetostatic modes in ferromagnetic spheres : 35th Annual conference on magnetism and magnetic materials (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 5724-5726 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A first-order instability theory for magnetostatic modes in ferromagnetic spheres has been developed. The analysis is based on the interaction of three modes: the uniform mode pumped at microwave frequency ωp and a pair of magnetostatic modes at lower frequencies which sum to ωp. The magnetostatic mode instability arises when the pump microwave field amplitude exceeds some threshold. The theory yields (i) selection rules for the magnetostatic mode pairs with a nonzero coupling to the uniform mode, (ii) a characteristic equation for the frequencies of these modes, and (iii) microwave field threshold amplitudes for the parametric excitation of the mode pairs. For each mode pair, one or more sharp threshold minima are found. The superposition of these sharp minima resembles the complicated structure observed in the subsidiary absorption butterfly curve for single-crystal yttrium-iron-garnet spheres.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.347899
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...