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
Filter
  • 1995-1999  (25)
  • 1
    Electronic Resource
    Electronic Resource
    Crystal structure and electronic transport property of perovskite manganese oxides with a fixed tolerance factor (1997)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 70 (1997), S. 1900-1902 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The structural and electronic transport properties of ABO3-type compounds La2/3−xRxCa1/3MnO3(R=Pr, Nd, Sm, Eu, Gd, Tb, Dy, Y, Er, and Tm) with a fixed tolerance factor of t=0.91137 is studied. Similar structure deformation, characterized by the nearly constant average Mn–O, A–O distances and Mn–O–Mn bond angles, is observed in different compounds. The metal–semiconductor transition shows a strong R dependent feature. The transition temperature decreases monotonously from 187 to 77.6 K as R varies from Tm to Pr, with a corresponding maximum resistivity ranging from 2.34 to 6.17×104 Ω cm. Very different magnetoresistance effects are also observed in this series of compounds. By assuming the presence of inhomogeneous local lattice distortions due to ions with different sizes at A sites and their mismatch with B ions, the lattice effects can be understood qualitatively. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.118725
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Magnetism of perovskite manganese oxide La1/3Nd1/3Ca1/3MnO3 (1997)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 82 (1997), S. 4687-4689 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Magnetism of bulk La1/3Nd1/3Ca1/3MnO3 with a magnetoresistance ratio as high as −96% in a field of 0.67 T is investigated. Two shoulders are observed on both thermal magnetization curves and magnetization isotherms. A magnetic inhomogeneity model, i.e., simultaneous occurrence of ferromagnetic La-rich domains and nonferromagnetic Nd-rich domains in the compound, is proposed. The model gives a satisfactory explanation for the experimental results. It is argued that a field-induced magnetic transition occurs in the Nd-rich phase and the coexisting La-rich phase can promote the magnetic transition. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.366210
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Structural and magnetoresistive properties of La0.7Ca0.3Mn0.96(Al1−xInx)0.04O3 (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 3619-3622 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Structural, magnetic, and transport properties of ABO3-type La0.7Ca0.3Mn0.96(Al1−xInx)0.04O3 are investigated. Different structure deformation from that in the A-site doping, characterized by the synchronous variation of the lattice constants b with c/(square root of 2) versus the content of In in the compounds, is observed. The metal–semiconductor transition shows a strong In content dependence. The transition temperature decreases monotonously from 180.7 to 103.4 K as x varies from 0 to 1, with a corresponding maximum resistivity ranging from 2.9 to 410.8 Ω cm. The magnetoresistive properties of the materials are strongly affected by the size mismatch between A- and B-site ions, and a relation similar to that presented by Hwang et al. [Phys. Rev. Lett. 75, 914 (1995)] is observed though controlling of the tolerance factor, is realized by B-site doping. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.369723
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Giant magnetoresistance effect in bulk La1/3Nd1/3Ca1/3MnO3 at low field (1996)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 69 (1996), S. 424-426 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A magnetoresistance ratio as high as −96% in a low field of 0.67 T is achieved in bulk La1/3Nd1/3Ca1/3MnO3. The magnetization exhibits a transition from a low moment state to a high moment state with decreasing temperature, accompanied by a thermal hysteresis of the magnetization. The magnetic transition might be an order-order transition and would be responsible for the observed giant magnetoresistance effect in the compound at low field. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.118082
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Doping effects arising from Fe and Ge for Mn in La0.7Ca0.3MnO3 (1998)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 73 (1998), S. 2998-3000 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Structural, magnetic, and transport properties of polycrystalline La0.7Ca0.3Mn1−xFexO3 and La0.7Ca0.3Mn1−xGexO3 are experimentally studied. Single-phase samples are obtained in the range x=0–0.12 for Fe, and x=0–0.06 for Ge. There are no appreciable structure changes due to the introduction of Fe and Ge. The Mn-site doping favors a reduced magnetic/resistive transition, at rates of ∼22 K for 1% Fe and ∼28 K for 1% Ge, and an elevated resistivity. No metal–insulator transition occurs when the content of Fe exceeds ∼0.1. The enhanced doping effects in La0.7Ca0.3Mn1−xGexO3 can be ascribed to the reduced hole concentration noting that the presence of Fe and Ge influence the contents of mobile eg electrons and holes in the compounds, respectively. Equivalence of the effects from Fe and Ge doping, respectively, to those due to eg electron and hole trapping and the relation between Mn- and O-site doping are discussed. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.122656
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Complex magnetic and electronic transport properties of (La,Gd)1−xSrxMnO3+δ perovskites (1997)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 71 (1997), S. 3718-3720 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The magnetic and transport properties of (La,Gd)1−xSrxMnO3+δ (x=0.15, 0.2, 0.25, and 0.3) with a fixed tolerance factor t=0.913 are studied. Special attention is paid to the postannealing effects of the compounds. Two magnetic transitions are observed in samples x=0.2 and 0.25 which are single phase in structure according to powder x-ray diffraction. Different effects on the two resulting states are produced by the postannealing. Accompanying the weakening of the state at lower temperature, the magnetic ordering of high-temperature state is enhanced substantially by the introduction of excess oxygen due to annealing the samples in O2. One typical paramagnetic–ferromagnetic transition occurs in samples x=0.15 and 0.3. There is a strong indication that the magnetic states in x=0.15 and 0.3 are, respectively, the developments of the high- and low-temperature states in x=0.2 (or x=0.25). The occurrence of two metal–semiconductor transitions in x=0.15–0.25 and their responses to postannealing suggest magnetic heterogeneity in the compound. By assuming the coexistence of vacancy-rich and vacancy-deficient domains in the compounds, these observations can be understood qualitatively. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.120492
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Effects of inhomogeneous oxygen content in (La,Gd)0.7Ca0.3MnO3+δ perovskites (1998)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 72 (1998), S. 3208-3210 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Magnetoresistance properties of compounds with the same formula La0.7−xGdxCa0.3MnO3+δ (x=0, 0.04) but synthesized by the solid-state reaction method from different starting materials are studied. Nearly stoichiometric compounds are obtained when La(OH)3 is used for sample preparation. However, under the same condition, La2O3 causes considerable oxygen deficiency in resulting samples, characterized by a broad metal–semiconductor transition far below the magnetic transition. Inhomogeneous distribution of the oxygen content in compounds (an inhomogeneity beyond the detection of powder x-ray diffraction) can occur when both La2O3 and La(OH)3 coexist in the starting materials, leading to two metal–semiconductor transitions which are obviously developments of those in compounds prepared respectively from La2O3 and La(OH)3, and one magnetic transition corresponding to the upper resistive transition. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.121551
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Lattice effects on the magnetic and transport properties of La2/3−xNdxCa1/3MnO3 (1996)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 69 (1996), S. 3926-3928 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The magnetic and transport properties of La2/3−xNdxCa1/3MnO3 (x=0–0.67) are studied. Two magnetic transitions occur in compounds with composition x=0.1–0.4, leading to a low moment state at high temperature and a high moment state at low temperature. A metal–insulator transition was observed for x≤0.4 between the two magnetic transitions. An electronic and magnetic phase diagram is depicted on a temperature–tolerance factor plane. The interesting feature of this diagram is the appearance of a new metamagnetic phase. Present investigation suggests that the tolerance factor is not the only parameter determining the lattice effects. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.117572
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Lattice effects on the magnetic and transport properties of La0.67−xSmxSr0.33CoO3 perovskites (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 75 (1999), S. 1772-1774 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Structural, magnetic, and transport properties of La0.67−xSmxSr0.33CoO3 with x=0.0, 0.05, 0.10, 0.15, 0.20, 0.25, and 0.30 are studied. The system exhibits a rhombohedrally distorted perovskite structure for x≤0.10. A rhombohedral–orthorhombic structure transition is detected in the doping range from x=0.15 to 0.25 and a pure orthorhombic structure appears in sample x=0.30. When cooled, the sample shows a metal-to-metal and a metal-to-semiconductor transition subsequently, with the upper one of magnetic nature. Both resistive transitions vary against doping level, with the first one from ∼235 to ∼200 K while the second one from ∼75 to ∼175 K corresponds to a change of x from 0.0 to 0.3. The introduction of Sm drives the system from a cluster-glass state in La0.67Sr0.33CoO3 into a spin-glass state in La0.37Sm0.30Sr0.33CoO3, accompanied by an enhancement of the semiconductive character of the compounds. The absence of strong Jahn–Teller effects and the spin-state transition may be responsible for the complex lattice effects in Co-based perovskites. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.124815
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    facet.materialart.
    Unknown
    Lattice effects on the magnetic and transport properties of La0.67−xSmxSr0.33CoO3 perovskites (1999)
    American Institute of Physics
    Details
    Publication Date: 1999-09-20
    Print ISSN: 0003-6951
    Electronic ISSN: 1077-3118
    Topics: Physics
    Published by American Institute of Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...