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Papers by Catherine Dubourdieu
Nature communications, Jan 29, 2024
june 29-july 4 2014International audienceno abstrac
11-15 mai 2015International audienceno abstrac
ECS Meeting Abstracts, 2005
not Available.
Journal of Materials Chemistry C, 2020
Transferable highly (001)-oriented textured ferroelectric BaTiO3 thin films have been achieved on... more Transferable highly (001)-oriented textured ferroelectric BaTiO3 thin films have been achieved on a graphene monolayer for wearable devices like sensors and actuators for future “Internet of Things” era.
Physica C: Superconductivity, 1998
A quantitative study of the effect of a-axis grains (the a-axis is perpendicular to the substrate... more A quantitative study of the effect of a-axis grains (the a-axis is perpendicular to the substrate plane) on the microwave surface resistance in epitaxial YBa2Cu3O7−x films is reported. The films were grown by Metal Organic Chemical Vapor Deposition on MgO and LaAlO3 substrates. The fraction of a-axis grains %a has been varied in the range 0–70% by changing the oxygen partial pressure during the growth. A clear correlation between the surface resistance Rs(0.85Tc), measured at 87 GHz, and the volumic fraction %a is found. At variance, the residual surface resistance Rs(4.2 K) does not correlate to %a.
Nature Physics, 2017
Ferroelectricity on the nanoscale has been the subject of much fascination in condensed-matter ph... more Ferroelectricity on the nanoscale has been the subject of much fascination in condensed-matter physics for over half a century. In recent years, multiple reports claiming ferroelectricity in ultrathin ferroelectric films based on the formation of remnant polarization states, local electromechanical hysteresis loops, and pressure-induced switching were made. However, similar phenomena were reported for traditionally non-ferroelectric materials, creating a significant level of uncertainty in the field. Here we show that in nanoscale systems the ferroelectric state is fundamentally inseparable from the electrochemical state of the surface, leading to the emergence of a mixed electrochemical-ferroelectric state. We explore the nature, thermodynamics, and thickness evolution of such states, and demonstrate the experimental pathway to establish its presence. This analysis reconciles multiple prior studies, provides guidelines for studies of ferroelectric materials on the nanoscale, and establishes the design paradigm for new generations of ferroelectric-based devices.
Nano letters, Jan 9, 2016
Memristive devices, whose conductance depends on previous programming history, are of significant... more Memristive devices, whose conductance depends on previous programming history, are of significant interest for building nonvolatile memory and brain-inspired computing systems. Here, we report half-integer quantized conductance transitions G = (n/2) (2e(2)/h) for n = 1, 2, 3, etc., in Cu/SiO2/W memristive devices observed below 300 mV at room temperature. This is attributed to the nanoscale filamentary nature of Cu conductance pathways formed inside SiO2. Retention measurements also show spontaneous filament decay with quantized conductance levels. Numerical simulations shed light into the dynamics underlying the data retention loss mechanisms and provide new insights into the nanoscale physics of memristive devices and trade-offs involved in engineering them for computational applications.
Thin Solid Films, 2001
We illustrate the capabilities of pulsed-liquid injection metal-organic chemical vapor deposition... more We illustrate the capabilities of pulsed-liquid injection metal-organic chemical vapor deposition in the nano-engineering of complex oxides with results obtained on (La Sr MnO ySrTiO) (LSMOySTO) superlattices. Superlattices with ultrathin 0.7 0.3 3 3 15 films of a few monolayers have been successfully prepared, as shown by synchrotron radiation diffraction experiments. Laue oscillations were observed between the satellite peaks, indicating a smooth upper surface. Sets of superlattices with varying LSMO or STO thickness were synthesized on different substrates (LaAlO , SrTiO , MgO). By varying the relative thickness of 3 3 each compound and changing the substrate, the strain in the stackings could be changed.
Nature communications, Jan 29, 2024
june 29-july 4 2014International audienceno abstrac
11-15 mai 2015International audienceno abstrac
ECS Meeting Abstracts, 2005
not Available.
Journal of Materials Chemistry C, 2020
Transferable highly (001)-oriented textured ferroelectric BaTiO3 thin films have been achieved on... more Transferable highly (001)-oriented textured ferroelectric BaTiO3 thin films have been achieved on a graphene monolayer for wearable devices like sensors and actuators for future “Internet of Things” era.
Physica C: Superconductivity, 1998
A quantitative study of the effect of a-axis grains (the a-axis is perpendicular to the substrate... more A quantitative study of the effect of a-axis grains (the a-axis is perpendicular to the substrate plane) on the microwave surface resistance in epitaxial YBa2Cu3O7−x films is reported. The films were grown by Metal Organic Chemical Vapor Deposition on MgO and LaAlO3 substrates. The fraction of a-axis grains %a has been varied in the range 0–70% by changing the oxygen partial pressure during the growth. A clear correlation between the surface resistance Rs(0.85Tc), measured at 87 GHz, and the volumic fraction %a is found. At variance, the residual surface resistance Rs(4.2 K) does not correlate to %a.
Nature Physics, 2017
Ferroelectricity on the nanoscale has been the subject of much fascination in condensed-matter ph... more Ferroelectricity on the nanoscale has been the subject of much fascination in condensed-matter physics for over half a century. In recent years, multiple reports claiming ferroelectricity in ultrathin ferroelectric films based on the formation of remnant polarization states, local electromechanical hysteresis loops, and pressure-induced switching were made. However, similar phenomena were reported for traditionally non-ferroelectric materials, creating a significant level of uncertainty in the field. Here we show that in nanoscale systems the ferroelectric state is fundamentally inseparable from the electrochemical state of the surface, leading to the emergence of a mixed electrochemical-ferroelectric state. We explore the nature, thermodynamics, and thickness evolution of such states, and demonstrate the experimental pathway to establish its presence. This analysis reconciles multiple prior studies, provides guidelines for studies of ferroelectric materials on the nanoscale, and establishes the design paradigm for new generations of ferroelectric-based devices.
Nano letters, Jan 9, 2016
Memristive devices, whose conductance depends on previous programming history, are of significant... more Memristive devices, whose conductance depends on previous programming history, are of significant interest for building nonvolatile memory and brain-inspired computing systems. Here, we report half-integer quantized conductance transitions G = (n/2) (2e(2)/h) for n = 1, 2, 3, etc., in Cu/SiO2/W memristive devices observed below 300 mV at room temperature. This is attributed to the nanoscale filamentary nature of Cu conductance pathways formed inside SiO2. Retention measurements also show spontaneous filament decay with quantized conductance levels. Numerical simulations shed light into the dynamics underlying the data retention loss mechanisms and provide new insights into the nanoscale physics of memristive devices and trade-offs involved in engineering them for computational applications.
Thin Solid Films, 2001
We illustrate the capabilities of pulsed-liquid injection metal-organic chemical vapor deposition... more We illustrate the capabilities of pulsed-liquid injection metal-organic chemical vapor deposition in the nano-engineering of complex oxides with results obtained on (La Sr MnO ySrTiO) (LSMOySTO) superlattices. Superlattices with ultrathin 0.7 0.3 3 3 15 films of a few monolayers have been successfully prepared, as shown by synchrotron radiation diffraction experiments. Laue oscillations were observed between the satellite peaks, indicating a smooth upper surface. Sets of superlattices with varying LSMO or STO thickness were synthesized on different substrates (LaAlO , SrTiO , MgO). By varying the relative thickness of 3 3 each compound and changing the substrate, the strain in the stackings could be changed.