Heidemarie Schmidt

Prof. Dr. Heidemarie Schmidt


Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 November 2010 in Materials
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Journal Article
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SZShengqiang Zhou
Shengqiang Zhou
HSHeidemarie Schmidt
Heidemarie Schmidt
Diluted ferromagnetic semiconductors (FMS) are in the focus of intense research due to their potential applications in spintronics and their striking new physical properties. So far Mn-doped III-V compound semiconductors such as GaMnAs are the most important and best understood ones, but they are ferromagnetic only at well below room temperature. An interesting alternative could be magnetic semiconductors based on elemental semiconductors, also owing to their compatibility with Si microelectronics. In the last decades, considerable amount of work has been devoted to fabricate Mn-doped Ge and Si FMS. In this article, the structural, magnetic and magneto-transport properties of Mn-doped Ge and Si will be reviewed.

10 April 2023 in Nanomaterials
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XZXianyue Zhao
Xianyue Zhao
SMStephan Menzel
Stephan Menzel
IPIlia Polian
Ilia Polian
HSHeidemarie Schmidt
Heidemarie Schmidt
NDNan Du
Nan Du
This review provides a comprehensive examination of the state-of-the-art research on resistive switching (RS) in BiFeO3 (BFO)-based memristive devices. By exploring possible fabrication techniques for preparing the functional BFO layers in memristive devices, the constructed lattice systems and corresponding crystal types responsible for RS behaviors in BFO-based memristive devices are analyzed. The physical mechanisms underlying RS in BFO-based memristive devices, i.e., ferroelectricity and valence change memory, are thoroughly reviewed, and the impact of various effects such as the doping effect, especially in the BFO layer, is evaluated. Finally, this review provides the applications of BFO devices and discusses the valid criteria for evaluating the energy consumption in RS and potential optimization techniques for memristive devices.

14 July 2021 in Journal of Vacuum Science & Technology A
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EKEmanuel Knehr
Emanuel Knehr
MZMario Ziegler
Mario Ziegler
SLSven Linzen
Sven Linzen
KIKonstantin Ilin
Konstantin Ilin
PSPatrick Schanz
Patrick Schanz
MSMichael Siegel
Michael Siegel
Superconducting niobium nitride thin films are used for a variety of photon detectors, quantum devices, and superconducting electronics. Most of these applications require highly uniform films, for instance, when moving from single-pixel detectors to arrays with a large active area. Plasma-enhanced atomic layer deposition (ALD) of superconducting niobium nitride is a feasible option to produce high-quality, conformal thin films and has been demonstrated as a film deposition method to fabricate superconducting nanowire single-photon detectors before. Here, we explore the property spread of ALD-NbN across a 6-in. wafer area. Over the equivalent area of a 2-in. wafer, we measure a maximum deviation of 1% in critical temperature and 12% in switching current. Toward larger areas, structural characterizations indicate that changes in the crystal structure seem to be the limiting factor rather than film composition or impurities. The results show that ALD is suited to fabricate NbN thin films as a material for large-area detector arrays and for new detector designs and devices requiring uniform superconducting thin films with precise thickness control.

15 December 2008 in Journal of Applied Physics
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SMSven Müller
Sven Müller
Michael LorenzMichael Lorenz
Michael Lorenz
CCChristian Czekalla
Christian Czekalla
GBGabriele Benndorf
Gabriele Benndorf
HHHolger Hochmuth
Holger Hochmuth
CRCarsten Ronning
Carsten Ronning
Pulsed laser deposited ZnO films were implanted with vanadium ions using ion energies between 30 and 250 keV with different fluences yielding vanadium concentrations in the range between 0.8 and 5 at. % . After annealing under oxygen ambient at 800 °C , a broad luminescence band observed by photoluminescence covers nearly the total visible spectral region. This luminescence is a superposition of different bands triggered by the incorporated V and remaining implantation defects. The visual impression of the bright whitish emission of the implanted ZnO has been quantified using the color space map of the Commission internationale de l’Éclairage. Furthermore, the intensity of the white emission strongly increases with increasing V concentration, whereas Ar-implanted reference sample shows only weak white emission.

18 February 2011 in Discover Nano
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HKHardeep Kumar
Hardeep Kumar
SGSantanu Ghosh
Santanu Ghosh
Devesh Kumar AvasthiDevesh Kumar Avasthi
Devesh Kumar Avasthi
DKDebdulal Kabiraj
Debdulal Kabiraj
AMArndt Mücklich
Arndt Mücklich
JSJean-Paul Stoquert
Jean-Paul Stoquert
Present work reports the elongation of spherical Ni nanoparticles (NPs) parallel to each other, due to bombardment with 120 MeV Au+9 ions at a fluence of 5 × 1013 ions/cm2. The Ni NPs embedded in silica matrix have been prepared by atom beam sputtering technique and subsequent annealing. The elongation of Ni NPs due to interaction with Au+9 ions as investigated by cross-sectional transmission electron microscopy (TEM) shows a strong dependence on initial Ni particle size and is explained on the basis of thermal spike model. Irradiation induces a change from single crystalline nature of spherical particles to polycrystalline nature of elongated particles. Magnetization measurements indicate that changes in coercivity (Hc) and remanence ratio (Mr/Ms) are stronger in the ion beam direction due to the preferential easy axis of elongated particles in the beam direction.

1 May 2009 in Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
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Journal Article
Closed access
DBDanilo Bürger
Danilo Bürger
SZShengqiang Zhou
Shengqiang Zhou
JGJörg Grenzer
Jörg Grenzer
HRHelfried Reuther
Helfried Reuther
WAWolfgang Anwand
Wolfgang Anwand
HSHeidemarie Schmidt
Heidemarie Schmidt