GLORIA

GEOMAR Library Ocean Research Information Access

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
    Magnetic anisotropy of thin film La0.7Ca0.3MnO3 on untwinned paramagnetic NdGaO3 (001) (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 3388-3392 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We describe in detail a method by which to establish the magnetic anisotropy of thin ferromagnetic films on strongly paramagnetic substrates that are slightly anisotropic. The film that we consider is composed of the much studied manganite La0.7Ca0.3MnO3 and the substrate is NdGaO3, a good lattice match. Below a Curie temperature Tc of 260 K it was found, using a vibrating sample magnetometer, that 72±3 nm La0.7Ca0.3MnO3 films grown epitaxially by pulsed laser deposition on untwinned orthorhombic NdGaO3 (001) substrates exhibit uniaxial anisotropy with K=(3.6±0.1)×105 erg cm−3. The easy direction is along [110] of the pseudocubic unit cell, i.e., diagonal to the O–Mn–O bond directions and parallel to the side of the actual unit cell which is orthorhombic. We attribute an 11±4% loss of the low temperature moment to the proximity of the paramagnetic substrate rather than to stress. It is argued that stress is minimal such that the observed anisotropy must be magnetocrystalline. Both the reduction in moment and the anisotropy must be taken into account when designing thin film experiments. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1347957
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Resistance of a domain wall in La0.7Ca0.3MnO3 (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 6287-6290 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Although colossal magnetoresistance (CMR) materials exhibit large changes in electrical resistance (up to 106%), large magnetic fields (several tesla) must be applied. To obtain a sizeable low-field effect (〈102% in several millitesla), it is necessary to incorporate structural discontinuities such as grain boundaries, or other types of interfaces. The potential for applications, however, remains limited because structural discontinuities increase electrical resistance by several orders of magnitude and hence create noise. Moreover, it has proven to be difficult to fabricate structural discontinuities reproducibly. We have attempted to investigate discontinuities that are purely magnetic via transport measurements through a precisely controlled number of magnetic domain walls of known area in thin film devices of the ferromagnetic CMR perovskite La0.7Ca0.3MnO3. A sharp low-field switching seen below ∼110 K is ascribed to the formation of a precise number of magnetic domain walls, each with resistance-area product 8×10−14 Ω m2 at 77 K. This is four orders of magnitude larger than expected, suggesting that the domain walls contain an additional structure. Our findings demonstrate that CMR devices are capable of low-noise low-field switching, and suggest the possibility of exploiting a hitherto unexpected intrinsic effect reproducibly and therefore commercially. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.371687
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Dependence on film thickness of grain boundary low-field magnetoresistance in thin films of La0.7Ca0.3MnO3 (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 6970-6972 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The magnetoresistance of grain boundaries in the perovskite manganites is being studied, both in polycrystalline materials, and thin films grown on bicrystal substrates, because of interest in low-field applications. In this article we show that epitaxial films grown on SrTiO3 bicrystal substrates of 45° misorientation show magnetoresistance behavior which is strongly dependent on the thickness of the film. Thin films, e.g., 40 nm, can show a large low-field magnetoresistance at low temperatures, with very sharp switching between distinct high and low resistance states for fields applied in plane and parallel to the boundary. Thicker films show a more complex behavior of resistance as a function of field, and the dependence on the angle between the applied field and the grain boundary is altered. These changes in magnetoresistance behavior are linked to the variation in morphology of the films. Thin films are coherently strained, due to the mismatch with the substrate, and very smooth. Thicker films relax, with the formation of defects, and hence different micromagnetic behavior. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1362648
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Low field magnetotransport in La0.7Sr0.3MnO3 films : 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. 7157-7159 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have observed a strong correlation between the degree of epitaxy and the low field resistance versus field R(H) behavior in highly textured La0.7Sr0.3MnO3 films grown by pulsed laser deposition on SrTiO3 substrates. Highly epitaxial films show a small temperature dependent low field hysteretic R(H) peak near the magnetic ordering temperature (Tc), when the applied field is parallel to the transport current (J(parallel)H). In contrast, films with reduced epitaxy show a much larger low field hysteretic R(H) behavior with a pronounced in-plane angular dependence. The magnitude of this response grows with decreasing temperature below Tc. Our data and analysis suggest that even low angle grain boundaries play a fundamental role in transport properties in colossal magnetoresistive materials. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.367627
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Magnetoresistance of artificial La0.7Sr0.3MnO3 grain boundaries as a function of misorientation angle (1998)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 72 (1998), S. 2038-2040 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The resistance of polycrystalline doped LaMnO3 materials has been shown to be highly sensitive to low magnetic fields. To enable direct study of the properties of isolated grain boundaries we have grown epitaxial La0.7Sr0.3MnO3 films on a series of bicrystal substrates with different misorientation angles and patterned the films into a Wheatstone bridge geometry. We show that the grain boundary resistance and its magnetic field dependence vary strongly with the misorientation angle. The temperature dependence of the grain boundary resistance is also presented. We have obtained resistance changes of over 3% in fields of 2 mT at 300 K. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.121257
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Coherent magnetic reversal in half-metallic manganite tunnel junctions (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 77 (2000), S. 3803-3805 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report coherent magnetization reversal in the La0.7Ca0.3MnO3/NdGaO3/La0.7Ca0.3MnO3 tunnel junctions probed by spin-polarized tunneling. The junction resistance shows an extremely sharp switching with distinct binary resistances and its two-dimensional angular dependence reveals two different magnetic anisotropies in play in the top and bottom La0.7Ca0.3MnO3 electrodes. The large bottom electrode (50×2000 μm) shows the effective twofold crystalline anisotropy and the top electrode (6×6 μm) shows an additional fourfold anisotropy. The geometrical expression of the switching fields in two-dimensional polar coordinates provides evidence that the coherent magnetization reversal of the junctions, particularly the top electrode, closely resembles the ideal coherent rotation model. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1329870
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Magnetization reversal probed by spin-polarized tunneling (2002)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 80 (2002), S. 2722-2724 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report magnetic reversal processes in the magnetic tunnel junction (MTJ) based on a half metallic manganite, La0.7Ca0.3MnO3 by comprehensive spin-polarized tunneling (SPT) measurements. The large tunnel magnetoresistance up to 77% of (Rap−Rp)/Rap in the present MTJ is highly sensitive to the local magnetization fluctuation in the ferromagnetic electrodes and thus enables us to establish an instantaneous one-to-one correlation between the magnetization reversal and the SPT with the two-dimensional SPT measurements. We have found the systematic angular variations of the SPT features in the resistance-field curves, and based on the observed angular dependences, we propose a crucial role of the edge-domain pinning and the resultant multi-domain breakup for the magnetization reversal. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1469678
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Contact dermatitis in tie and dye industry Workers (1985)
    Oxford, UK : Blackwell Publishing Ltd
    Contact dermatitis 12 (1985), S. 0 
    Details
    ISSN: 1600-0536
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: A survey of the ‘Tie and Dye’ industry of Jodhpur City in India was made to investigate occupational dermatoses. 49 (16.6%) of 250 workers had incapacitating dermatitis. Skin legions were seen mostly over the dorsa of the hands and fingers. 26 patients were patch tested with various dyes and chemicals; 14 were positive. Fast Red RC sail was the most potent sensitizer. Other dyes showing positive reactions were Orange GC salt, Bordeaux GP salt. Blue B salt, Red B base and naphthol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1600-0536.1985.tb01037.x
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Single atom, peri-bridged arenes: 1-alkylidene-1H-cyclobuta[de]naphthalenes and .DELTA.1,1-bi-1H-cyclobuta[de]naphthalene (1991)
    s.l. : American Chemical Society
    The @journal of organic chemistry 56 (1991), S. 1663-1666 
    Details
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/jo00004a057
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Current–voltage characteristics and electrical transport properties of grain boundaries in La1−x(Sr/Ca)xMnO3 (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 7263-7266 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Grain boundaries in doped lanthanum manganites have been shown to have a large low-field magnetoresistance. However, the mechanism of electrical transport across grain boundaries, and the origin of the low-field magnetoresistance, are not well understood. Models based on scattering at domain walls, spin-polarized tunneling and depression of the Curie temperature due to strain near the grain boundary have all been proposed. This article reports detailed studies of the transport properties of artificial grain boundaries formed in a variety of thin films grown on bicrystal substrates. Resistance versus field sweeps on all grain boundary devices showed strong low-field magnetoresistance and the effect of individual domain motion at the grain boundary has been observed in single grain boundaries. In all cases, current versus voltage characteristics were highly non-ohmic, and reminiscent of an electron tunneling process. However, the magnetic dependence of the current–voltage characteristics implies that the magnetoresistance may be unrelated to tunneling. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.370542
    Location Call Number Limitation 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...