By Dr. Jutta Schwarzkopf, Leibniz-Institut für Kristallzüchtung, Berlin
16.05.2023 1:15 pm | Bd.600, R.301 CHyN
Abstract:
A promising way to tune the ferroelectric properties of complex oxides is to deliberately
modify the crystalline structure of these materials. This can be achieved by the deposition of thin oxide
films, where lattice strain is introduced by the heteroepitaxial growth on lattice mismatched
substrates. However, a directive tuning of the functional properties of thin films requires a detailed
understanding of the correlation between lattice strain and ferroelectric phase formation as well as the
availability of oxide substrates with tailored lattice mismatch. A very suitable growth method that
permits the growth of high-quality layers for this purpose is given by the metal-organic vapor phase
epitaxy (MOVPE) technique. It offers the advantages of high oxygen partial pressure, independent
control of all constituents, growth nearby thermodynamic equilibrium and large scale-up potential. In
my talk, I will discuss the influence of lattice strain in the material system Potassium-Sodium-Niobate
(K,Na)NbO3. (K,Na)NbO3 is a lead-free, environmentally friendly material which offers as bulk material
excellent piezoelectric and electromechanical properties, high Curie temperature and good thermal
stability. However, for most applications (like memory devices, actuators, sensors or RF devices),
reproducible growth of epitaxial films is necessary, which is still challenging due to the high volatility of
Na and K. Growth of epitaxially strained (K,Na)NbO3 thin films on IKZ own oxide substrates will be
discussed with regard to the impact of lattice strain on the ferro-/piezoelectric properties of the films.
As application example, the propagation of surface acoustic waves and the use of thin films in
biosensors are addressed.
Summer Group Barbecue
NewsCredit: Mehmet Bayindir
The discovery of luminescent nanocluster glass (NCG) highlighted in Nature
NewsOur recent JACS article on the luminescent nanocluster glass (NCG) is highlighted by Nature. [ Nature Research Highlight ]
An X-ray image of a fish is captured with the use of a glass that has an unusual internal structure. Credit: Chunwei Dong, Mehmet Bayindir, Osman Bakr/KAUST
Epitaxial growth of lead-free ferroelectric (K,Na)NbO3 thin films and the impact of strain
SeminarsBy Dr. Jutta Schwarzkopf, Leibniz-Institut für Kristallzüchtung, Berlin
16.05.2023 1:15 pm | Bd.600, R.301 CHyN
Abstract:
A promising way to tune the ferroelectric properties of complex oxides is to deliberately
modify the crystalline structure of these materials. This can be achieved by the deposition of thin oxide
films, where lattice strain is introduced by the heteroepitaxial growth on lattice mismatched
substrates. However, a directive tuning of the functional properties of thin films requires a detailed
understanding of the correlation between lattice strain and ferroelectric phase formation as well as the
availability of oxide substrates with tailored lattice mismatch. A very suitable growth method that
permits the growth of high-quality layers for this purpose is given by the metal-organic vapor phase
epitaxy (MOVPE) technique. It offers the advantages of high oxygen partial pressure, independent
control of all constituents, growth nearby thermodynamic equilibrium and large scale-up potential. In
my talk, I will discuss the influence of lattice strain in the material system Potassium-Sodium-Niobate
(K,Na)NbO3. (K,Na)NbO3 is a lead-free, environmentally friendly material which offers as bulk material
excellent piezoelectric and electromechanical properties, high Curie temperature and good thermal
stability. However, for most applications (like memory devices, actuators, sensors or RF devices),
reproducible growth of epitaxial films is necessary, which is still challenging due to the high volatility of
Na and K. Growth of epitaxially strained (K,Na)NbO3 thin films on IKZ own oxide substrates will be
discussed with regard to the impact of lattice strain on the ferro-/piezoelectric properties of the films.
As application example, the propagation of surface acoustic waves and the use of thin films in
biosensors are addressed.
Stem cell-derived neurons on nanowire array
NewsNanowire arrays interfaced with biological cells have been demonstrated to be potent tools for advanced applications such as sensing, stimulation, or drug delivery. This study published in Advanced Materials Interfaces demonstrates the generation of functional human iPSC-derived neurons on nanowire arrays with varying geometrical specifications. The cell/nanowire interactions range from fakir-like states to nanowire-encapsulating states depending on the array characteristics. The neurons are functional with similar kinetics of the action potentials highlighting the equivalence of the nanowire arrays for neuronal differentiation.
Opening: Master and Bachelor
UncategorizedAd_Master_vW_final
Our research in the Universität Hamburg magazine „19NEUNZEHN“
NewsThe research of M.Sc. Jann Harberts on neurons cultivated on tailor-made artificial substrates has been presented in the latest Universität Hamburg magazine “19NEUNZEHN” (inside cover and on page 22).
Press Release by Nanoscribe – Cell-culture microarchitectures for 3D neuronal networks
NewsA press release entitled “Cell-culture microarchitectures for 3D neuronal networks” has been published by Nanoscribe GmbH referring to the work of Cornelius Fendler published in Advanced Biosystems.
Tech Note – Together with Zeiss – Fabrication and Characterization of Nanofluidic Devices for DNA Optical Mapping
NewsA tech note entitled “Fabrication and Characterization of Nanofluidic Devices for DNA Optical Mapping” has been published by Carl Zeiss Microscopy GmbH, Germany and Parisa Bayat, Robert H. Blick, and Irene Fernández-Cuesta.
New Publication (Co-authorship): “Electrochemical Engineering of Nanoporous Materials for Photocatalysis: Fundamentals, Advances, and Perspectives” in MDPI Catalysts
NewsA joined publication entitled “Electrochemical Engineering of Nanoporous Materials for Photocatalysis: Fundamentals, Advances, and Perspectives” with the group of Dr. Abel Santos (University Adelaide) has been publishedin ACS Langmuir
Abstract: Photocatalysis comprises a variety of light-driven processes in which solar energy is converted into green chemical energy to drive reactions such as water splitting for hydrogen energy generation, degradation of environmental pollutants, CO2 reduction and NH3 production. Electrochemically engineered nanoporous materials are attractive photocatalyst platforms for a plethora of applications due to their large effective surface area, highly controllable and tuneable light-harvesting capabilities, efficient charge carrier separation and enhanced diffusion of reactive species. Such tailor-made nanoporous substrates with rational chemical and structural designs provide new exciting opportunities to develop advanced optical semiconductor structures capable of performing precise and versatile control over light–matter interactions to harness electromagnetic waves with unprecedented high efficiency and selectivity for photocatalysis. This review introduces fundamental developments and recent advances of electrochemically engineered nanoporous materials and their application as platforms for photocatalysis, with a final prospective outlook about this dynamic field.
New Publication: “Low-Temperature Vapor-Solid Growth of ZnO Nanowhiskers for Electron Field Emission ” in MDPI Coatings
NewsA new publication “Low-Temperature Vapor-Solid Growth of ZnO Nanowhiskers for Electron Field Emission” from Stefanie and Carina has been published in MDPI Coatings.
Abstract: