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@PHDTHESIS{Waschk:830274,
      author       = {Waschk, Markus},
      title        = {{I}nterface phenomena in
                      {L}a$_{1/3}${S}r$_{2/3}${F}e{O}$_{3}$/{L}a$_{2/3}${S}r$_{1/3}${M}n{O}$_{3}$
                      heterostructures and a quest for p-electron magnetism},
      volume       = {157},
      school       = {RWTH Aachen},
      type         = {Dr.},
      address      = {Jülich},
      publisher    = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
      reportid     = {FZJ-2017-03847},
      isbn         = {978-3-95806-281-8},
      series       = {Schriften des Forschungszentrums Jülich. Reihe
                      Schlüsseltechnologien / Key Technologies},
      pages        = {IX, 205 S.},
      year         = {2017},
      note         = {RWTH Aache, Diss., 2017},
      abstract     = {Transition metal oxides (TMO's) show functionalities which
                      make them promising candidates for sensors and storage
                      devices in future information technologies, because of
                      electronic correlations and complex ordering phenomena. Such
                      devices will consist of heterostructures of different TMO's,
                      where interfaces can add additional functionalities, which
                      cannot be found in the individual constituents. The subtle
                      balance between electronic, spin, and lattice degrees of
                      freedom leads to a variety of quantum phenomena in TMO's and
                      results in an extreme sensitivity to external stimuli such
                      as pressure and magnetic fields. The use of thin films
                      increases the plethora of phenomena due to the reduced
                      dimensionality, and epitaxial strain. At the interface
                      completely new phenomena like magnetic interlayers between
                      two non-magnetic layers or metallic behavior between two
                      insulating materials may emerge, which cannot be found in
                      the bulk materials. The main part of this thesis is an
                      investigation of the system La$_{1/3}$Sr$_{2/3}$FeO$_{3}$
                      (LSFO) and La$_{2/3}$Sr$_{1/3}$MnO$_{3}$(LSMO). LSFO
                      contains a Verwey transition with a resistivity increase of
                      eight orders of magnitude from 300K to 10 K, coinciding with
                      an antiferromagnetic and a charge ordering transition. The
                      samples were prepared with two powerful oxide growth
                      methods, the high oxygen pressure sputtering, which was used
                      for the LSMO growth, and a state of the art oxide molecular
                      beam epitaxy system for the LSFO growth. The optimized
                      growth of the individual layers and the heterostructures
                      will be presented in detail. Furthermore, a detailed
                      investigation with regard to structural, magnetic, and
                      electronic properties will be shown. Single layers as well
                      as heterostructures grow epitaxially on a SrTiO$_{3}$
                      substrate, in spite of a transfer procedure from one
                      preparation chamber to another under atmosphere, which was
                      necessary for the growth of heterostructures. The
                      stoichiometric samples exhibit a good crystallinity and low
                      surface roughness. However, the interface morphology in the
                      heterostructures depends crucially on the growth order.
                      Significant iron interdiffusion from the pre-deposited LSFO
                      into the LSMO layer to at least nine unit cells is
                      observable for the system LSMO/LSFO, whereas the LSFO
                      deposited on LSMO exhibits a sharp interface with
                      interdiffusion restricted to two unit cells at most. The
                      differences of the magnetic properties are also remarkable.
                      The LSMO/LSFO sample shows an increased Curie temperature, a
                      reduced interface magnetization, and a vanishing exchange
                      bias effect, which is linked to the interdiffusion. In
                      contrast, the system LSFO/LSMO has a homogeneous
                      magnetization in the whole layer, but the macroscopic
                      magnetization measurements reveal an additional magnetic
                      impurity phase which persists at temperatures higher than
                      380 K, with a rather high coercive field. M(H) measurements
                      feature an inverted hysteresis at 110K and a strong field
                      cooling dependency of the magnetization at 10 K, which
                      includes a significant exchange bias effect. The second
                      investigated system belongs to a new class of magnetic
                      materials, namely those where magnetism is caused by
                      p-electrons as predicted by Gruber et al. [1] and Oja et al.
                      [2]. These materials provide new routes to future storage
                      devices as one can magnetically dope ferroelectric materials
                      like BaTiO3 to achieve artificial multiferroic materials.
                      The realization of such systems seems to be challenging and
                      only initial results of a BaTiO$_{3}$ bulk system and
                      KTaO$_{3}$/SrTiO$_{3}$ heterostructure can be presented.},
      cin          = {JCNS-2 / PGI-4 / JARA-FIT},
      cid          = {I:(DE-Juel1)JCNS-2-20110106 / I:(DE-Juel1)PGI-4-20110106 /
                      $I:(DE-82)080009_20140620$},
      pnm          = {144 - Controlling Collective States (POF3-144) / 524 -
                      Controlling Collective States (POF3-524) / 6212 - Quantum
                      Condensed Matter: Magnetism, Superconductivity (POF3-621) /
                      6213 - Materials and Processes for Energy and Transport
                      Technologies (POF3-621) / 6G4 - Jülich Centre for Neutron
                      Research (JCNS) (POF3-623)},
      pid          = {G:(DE-HGF)POF3-144 / G:(DE-HGF)POF3-524 /
                      G:(DE-HGF)POF3-6212 / G:(DE-HGF)POF3-6213 /
                      G:(DE-HGF)POF3-6G4},
      experiment   = {EXP:(DE-MLZ)DNS-20140101},
      typ          = {PUB:(DE-HGF)3 / PUB:(DE-HGF)11},
      url          = {https://juser.fz-juelich.de/record/830274},
}