ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
    Study on the coercivity of granular solid iron (1995)
    Springer
    Applied physics 61 (1995), S. 407-413 
    Details
    ISSN: 1432-0630
    Keywords: PACS: 75.60.Jp; 75.30.Gw
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract.  The iron granular solid, in which ultrafine iron particles are dispersed, has been prepared with both SiO2 and Cu matrices using the sol-gel method. The structure and morphology of these granular solid samples are investigated by X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). The magnetic properties are measured using a vibrating sample magnetometer with 20 kOe maximum applied field. It is found that the coercivity decreases very slightly with temperature from 80 to 300 K for these Fe–SiO2 and Fe–Cu granular solid samples with different average size of iron particles from 50 to 300 AÅ. The magnetic anisotropy has been obtained from the measured magnetization curves for these granular solid samples using the law of approach to saturation, and the obtained values of the effective magnetic anisotropy are all more than 106 erg/cm3, which are larger than the value of the magnetocrystalline anisotropy for bulk iron. The coercivity vs temperature for these granular solid samples has been calculated using the Kneller and Luborsky theory, in which the magnetic anisotropy values obtained from the law of approach to saturation are used. The trends of the calculated coercivity as a function of temperature are in reasonable agreement with the observations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01540115
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    ac magnetic susceptibility of YBa2Cu3O7−x (1988)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 64 (1988), S. 2533-2536 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: ac and dc magnetic susceptibilities were studied for relatively dense single-phase YBa2Cu3O7−x samples. The data are discussed in terms of sample defects.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.341637
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Phase formation in a Bi-Sr-Ca-Cu oxide superconductor (1988)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 64 (1988), S. 6795-6798 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The formation of different superconducting phases in the Bi-Sr-Ca-Cu-oxide system sensitively depends on the preparation procedures, particularly the firing temperatures. The tangled x-ray powder diffraction patterns of coexisting Bi2Sr2CaCu2Oy and Bi2Sr2Ca2Cu3Oy have been completely identified. The basic unit cells are of approximate tetragonal symmetry. The lattice constants of the latter have been determined to be 5.40×5.40×37.09 A(ring)3.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.342015
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Lower Cambrian vertebrates from south China (1999)
    [s.l.] : Macmillian Magazines Ltd.
    Nature 402 (1999), S. 42-46 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The first fossil chordates are found in deposits from the Cambrian period (545–490 million years ago), but their earliest record is exceptionally sporadic and is often controversial. Accordingly, it has been difficult to construct a coherent phylogenetic synthesis for the basal chordates. ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/46965
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Characteristics of the Mn and Co volume-doped acicular γ-Fe2O3 particles (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 5845-5848 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Mn- and Co-doped acicular γ-Fe2O3 particles with a coercivity of 923 Oe and Co content of 3.5 wt % have been prepared by a special process. This involves high-temperature ion diffusion, then step annealing. These particles exhibit a high magnetic thermal stability and low-temperature coefficient of coercivity. The latter demonstrates a striking contrast to the ordinary cobalt-body-doped γ-Fe2O3 particles. The induced uniaxial anisotropy constant Ku and the magnetocrystalline anisotropy constant K1 of the particles were determined by torque measurements. The novel properties of these particles are mainly due to the high uniaxial anisotropy, resulting from the anisotropic arrangements of cobalt ions. With the above characteristics and low Co content, these acicular particles can be one of the promising candidates for particulate high-density magnetic recording materials.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.358398
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Anisotropic giant magnetoresistance induced by magnetoannealing in Fe-Ag granular films : The 6th joint magnetism and magnetic materials (MMM)-intermag conference (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 6484-6486 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The effects of magnetoannealing on the giant magnetoresistance (GMR) in FexAg100−x granular films (X=15, 26, 29, 33, 37, and 60) were investigated. The thin films were annealed in a presence of magnetic field of 3 kOe at different temperatures of 300, 400, and 500 °C using various annealing times. It is found that the anisotropic GMR characteristics were developed when Fe-Ag granular thin films were annealed in the presence of a magnetic field. The anisotropic GMR characteristics of the thin films were closely related to the magnetic anisotropy developed along the field direction during magnetoannealing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.358233
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Influence of size and magnetocrystalline anisotropy on spin canting anomaly in fine ferrimagnetic particles : The 6th joint magnetism and magnetic materials (MMM)-intermag conference (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 6591-6593 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Fine equiaxed γ-CoxFe2−xO3 (x=0, 0.06) particles with a diameter ranging from 200 to 1000 A(ring) were prepared by chemical precipitation. The average crystallite sizes were determined from x-ray line broadening measurements. The saturation magnetization and magnetocrystalline anisotropy of the particles were determined by using the approach to saturation. An empirical linear dependence of the specific saturation magnetization σs on the specific surface area Sa of the fine crystallites was obtained in the form of σs(S)=σs(∞)(1−ASa). The slope A which reflects the surface spin canting anomaly is different for γ-Fe2O3 and γ-Co0.06Fe1.94O3 particles. Under the supposition of the fine crystallite consisting of two parts, i.e., the surface layer, whose magnetic moment cannot be turned entirely along the direction of the applied field, but makes an average canting angle with the field, and the inner part, whose magnetic moment can be aligned along the direction of the applied field, the above formula can be interpreted well. The different slope A for γ-Fe2O3 and γ-Co0.06Fe1.94O3 particles may be caused by the different anisotropies of the two series particles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.358203
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    A Mössbauer effect study on the acicular cobalt ferrite particles : The 6th joint magnetism and magnetic materials (MMM)-intermag conference (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 6900-6902 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The causes of the coercivity enhancement and the coercivity instability of acicular cobalt ferrite particles containing 0–9.2 wt % Fe2+ ions under the influence of magnetic field and temperature were investigated by means of transverse magnetic field annealing, torque, and Mössbauer experiments. The coercivity enhancement and the instability of Co modified iron oxide particles are closely related to the uniaxial magnetic anisotropy. A Fe2+-CO2+ pair model was proposed to explain the uniaxial magnetic anisotropy of Co modified iron particles. To verify the nature of the Fe2+-Co2+ pair, the probability of one or more Co ions appearing in the neighborhood of a B site Fe2+ ion was calculated using the chemical composition, the Mössbauer parameters, Pi(Fe+2) and Pi(Fe+3) and discussed conditions for forming the pair between the nearest-neighbor Co2+ and Fe2+ ion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.358109
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    X-ray photoelectron spectroscopy and Mössbauer study of Ho(Fe1−xMnx)2 compounds : The 6th joint magnetism and magnetic materials (MMM)−intermag conference (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 6903-6905 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Cubic Laves compounds Ho(Fe1−xMnx)2 (x=0, 0.1, 0.2, 0.3) were investigated by XPS and Mössbauer measurements. It was found that the binding energy (BE) of compounds obtained by XPS remains almost the same for all the compounds and no chemical shift (δ) of the core-electron binding energy was found, which implies that no charge transfer takes place from Mn atoms to Fe atoms due to Mn substitution. Mössbauer study has shown that the average hyperfine fields and the deduced Fe moment decrease with increasing Mn content. It is considered that the variation of isomer shift (IS) due to Mn substitution obtained by Mössbauer measurement is mainly due to the size effect since the isomer shift (δ) for the compounds are almost linearly dependent on the volume; electron transfers seem to be of minor importance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.358110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Effects of phosphorous doping on the stability of coercivity of cobalt-substituted acicular oxides (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 78 (1995), S. 409-412 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The effects of P doping on the coercivity and magnetic-thermal stability of Co-substituted iron oxides have been investigated by means of magnetic measurements, torque curves, and Mössbauer spectra. It is found that the P doping of cobalt-substituted acicular oxides promotes the coercivity and the stability with temperature of the coercivity. Then effects may be attributed to the increase of the cubic magnetocrystalline anisotropy constant K1 and the activation energy E, respectively. The Mössbauer results suggest that P ions are located in the neighborhood of the B-site Fe ions. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.360617
    Location Call Number Expected 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...