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
    Monograph available for loan
    Monograph available for loan
    Modelling changes in climate due to enhanced CO2, the role of atmospheric dynamics, cloud and moisture (1991)
    Bracknell : Hadley Centre for climate prediction and research
    Associated volumes
    Details Availability
    Call number: ZSP-192-13
    In: Climate research technical note
    Type of Medium: Monograph available for loan
    Pages: getr. Zählung
    Series Statement: Climate research technical note 13
    Language: English
    Location: AWI Reading room
    Branch Library: AWI Library
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    BOOK
    Link to Library Catalog
    get availability status
  • 2
    Electronic Resource
    Electronic Resource
    Effect of layering and doping on the magnetic anisotropy of the layered manganites La2−2xSr1+2xMn2O7 (x=0.3–0.4) (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 6621-6623 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Magnetization experiments were performed on a series of single crystals of the bilayer manganites La2−2xSr1+2xMn2O7. The magnetic anisotropy constants were determined by fitting expressions based on the tetragonal anisotropy energy to the magnetization curves. It is shown that there is a significant dipolar contribution to the first order anisotropy constant arising from the layered crystal structure. This contribution determines the magnetization direction in the doping range x=0.32–0.33 where the anisotropy due to the electronic structure is small. With increasing doping the magnetic anisotropy changes from strong uniaxial anong the c axis (K(approximate)2.5×106 erg/cm3) at x=0.3 to strong easy plane (K(approximate)−3.7×106 erg/cm3) at x=0.4 in an almost linear fashion. This evolution is explained through the change of the orbital nature of the eg electrons from predominantly d3z2−r2 to predominantly dx2−y2. On the samples displaying easy-plane anisotropy a small anisotropy in the basal plane of about −7×104 erg/cm3 was determined with (110) being the easy axis. An estimate of the spin-wave gap based on these results is in reasonable agreement with experimental determinations. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1357136
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Low-energy spin-wave excitations in the bilayer manganite La1.2Sr1.8Mn2O7 (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 5816-5818 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Inelastic neutron scattering experiments were performed on a single crystal of the bilayer manganite La1.2Sr1.8Mn2O7. Low-energy spin-wave excitations were observed along the c direction with a maximum energy of ∼ 0.5 meV at the zone boundary. The dispersion of these acoustic spin wave modes is modeled by a nearest-neighbor Heisenberg model with an interbilayer exchange interaction between neighboring spins in different bilayers of 0.048(1) meV and an anisotropy gap of Δ = 0.077(3) meV. These results confirm the two-dimensional nature of the spin correlations in the bilayer manganites, with a ratio of the in-plane to interbilayer interaction of ∼ 200. The temperature dependence of the energies and intensities of the spin wave excitations are in agreement with our earlier conclusion that the ferromagnetic transition is second order. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.372532
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Layered manganites: Magnetic structure at extreme doping levels (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 4352-4354 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report powder neutron diffraction results on the crystal and magnetic structures of the bilayer Ruddlesden–Popper phase Sr3Mn2O7−δ (δ=0.0, 0.45) and correlate these structures with their magnetic and transport properties. The δ=0.45 compound contains a large number of oxygen vacancies that are disordered in the MnO2 planes. As a result of this disordered vacancy structure, Sr3Mn2O6.55 is a nonmagnetic insulator. Sr3Mn2O7.0 (δ=0) is an antiferromagnetic insulator whose magnetic structure is related to that of the SrMnO3 perovskite. Comparison of this end-member compound to its doped congeners in the La2−2xSr1+2xMn2O7 series highlights the extreme sensitivity of magnetic structure to dopant concentration in these layered materials. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.370498
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Magnetic phase diagram of layered manganites in the highly doped regime (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 6618-6620 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The naturally layered colossal magnetoresistive manganites La2−2xSr1+2xMn2O7 exhibit an extremely varied range of magnetic and electronic behavior over a very narrow composition range between x=0.3 and x=0.5. The successful synthesis in our laboratories of compounds with nominally greater than 50%Mn4+ concentration has now allowed the study of this region of the phase diagram. Here we present detailed neutron diffraction measurements of these compounds with doping levels 0.5〈x〈1.0. As predicted by simple theories, the type-A layered antiferromagnetic (AF) structure is found at x∼0.5 and the type-G "rocksalt" AF structure at x=1.0. Between these two extremes is found a C-type structure (ferromagnetic rods parallel to b coupled antiferromagnetically to all neighboring rods) stabilized by orbital ordering of y2 states. Also in this Mn4+-rich regime is found a region in which no long-range magnetic order is observed. We discuss how semiempirical models can explain the variety of magnetic structures and how structural trends as a function of doping corroborate the unifying notion of a shift from in-plane to axial orbital occupation as the Mn4+ concentration is decreased. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1357135
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Role of intergrowths in the properties of naturally layered manganite single crystals (invited) : The 7th joint MMM-intermag conference on magnetism and magnetic materials (1998)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 83 (1998), S. 6385-6389 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Two-layered Ruddlesden–Popper phase SrO(La1−xSrxMnO3)2, with x=0.3 and 0.4, exhibits colossal magnetoresistance, a magnetic anisotropy which is strongly composition-dependent, very little remanence, and an anomalous low-field magnetization (M) plateau between the Curie temperature (TC) and T*∼300 K. The resistivity peaks near TC for both in-plane and out-of-plane currents. The magnetization plateau is not intrinsic to the crystal, but is attributed to intergrowth defects, consisting of one additional or missing SrO blocking layers, as observed in transmission electron micrographs. The intergrowths exhibit interesting two-dimensional magnetic behavior, for both the x=0.3 and 0.4 compositions. For x=0.4, M scales as (1−T/T*)β, with β=0.25±0.02. For x=0.3, the intergrowths exhibit an easy axis in the a-b plane due to the shape anisotropy, while for T〈TC, M lies along the c axis. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.367906
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Magnetic correlations in the bilayer manganite La1.2Sr1.8Mn2O7 : The 7th joint MMM-intermag conference on magnetism and magnetic materials (1998)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 83 (1998), S. 7348-7350 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Neutron scattering has been used to study the magnetic correlations in the double-layer manganite La1.2Sr1.8Mn2O7, which exhibits colossal magnetoresistance in the vicinity of the ferromagnetic transition at Tc=112 K. Over a large temperature range above Tc, there is evidence for two-dimensional magnetic correlations which peak in intensity at the transition. Although the in-plane correlations are predominantly ferromagnetic, a strong canting of spins in neighboring planes within the bilayers, at an angle that is dependent on both the temperature and magnetic field, is observed. There are indications of a crossover to three-dimensional critical scattering very close to Tc, but the nature of the phase transition has yet to be determined. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.367796
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Evidence for competing order parameters in the paramagnetic phase of layered manganites (invited) (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 6851-6856 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The magnetic field and temperature dependence of the magnetic susceptibility is studied for the ferromagnetic layered manganites SrO(La1−xSrxMnO3)2 in the composition range x=0.32–0.40. In the paramagnetic phase, the susceptibility exhibits an anomalous maximum at an intermediate magnetic field value. The size of this field-induced susceptibility enhancement increases dramatically with x from 10% for x=0.32 to 160% for x=0.40. The temperature dependence of the effect shows a maximum at T(approximate)1.1 TC for all x. Quantitative analysis in terms of the Landau theory of phase transitions enables us to identify a distortion of the free energy F in the paramagnetic phase that is associated with the susceptibility anomaly. This free energy distortion corresponds to a magnetic system that approaches a first order magnetic phase transition as the temperature is lowered toward TC. Such a behavior is indicative of a second, competing order parameter, which is identified as the recently observed charge density wave. In the immediate vicinity of TC, the anomaly disappears and the system seems to undergo a more conventional second order paramagnetic–ferromagnetic phase transition. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1360681
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Magneto-optical imaging of the first order spin-flop transition in the layered manganite La1.4Sr1.6Mn2O7 (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 5043-5045 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The spin-flop transition in the antiferromagnetic layered manganite La1.4Sr1.6Mn2O7 was studied using magnetization measurements and a high-resolution magneto-optical imaging technique. We report the direct observation of the formation of ferromagnetic domains appearing at the first order spin-flop transition. The magnetization process proceeds through nucleation of polarized domains at crystal defect sites and not through the expansion of polarized domains due to domain wall motion. A small magnetic hysteresis is caused by the difference between the mechanisms of nucleation and annihilation of domains in the mixed state. These results establish a direct link between the magnetic structure on the atomic scale as seen in neutron scattering and the macroscopic properties of the sample as seen in magnetization and conductivity measurements. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.373242
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    The irreversibility line of HgBa2CuO4+δ (1993)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 63 (1993), S. 693-695 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Using magnetization hysteresis loops we have determined the irreversibility line of polycrystalline samples of HgBa2CuO4+δ and Hg0.8Pb0.2Ba2CuO4+δ. The irreversibility line is found at rather high temperatures. It does not show the drastic depression with increasing temperature as is observed in highly anisotropic Bi/Tl-based CuO superconductors. At 77 K the irreversibility field is around 0.3 T, which is substantially higher than in Bi2Sr2CaCu2O8 and Bi2Sr2Ca2Cu3O10. The advantages of this material for large-scale applications are outlined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.109931
    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...