The invited talk was given at ISAF (International Symposium on Applications of Ferroelectrics), a leading conference in the field of ferroelectrics, which was in 2014 held in State College, USA. The project leader presented the results on the piezoelectric behavior of BiFeO3 ceramics. In particular, he showed the nonlinear piezoelectric response of BiFeO3 at low driving field frequencies, which is distinctly different from that of the morphotropic Pb(Zr,Ti)O3 (PZT). The mechanism that links the dynamics of the conductive domain walls in BiFeO3 with the macroscopic piezoelectric response was explained in detail.
B.04 Guest lecture
COBISS.SI-ID: 27726375The project collaborator dr. Andreja Benčan Golob was invited to the EMN meeting on perovskite, solar cells and hydrogen, in Xiamen, China. In the talk, she presented the results on the identification of charged defects at domain walls in BiFeO3 using state-of-the-art aberration corrected electron microscopy. Within this study we developed two analytical methods (EELS, HAADF) allowing chemical analysis at the atomic scale, which lead to the identification of iron (IV) ions and bismuth vacancies accumulated at the domain walls. These results made it possible to explain the mechanism of domain wall conduction in BiFeO3.
B.04 Guest lecture
COBISS.SI-ID: 30080551The postodoctoral collaborator of the project Julian Walker gave a talk on an international conference in Russia in 2014 on the project results related to the BiFeO3-SmFeO3 ceramic system. The presentation was focused on the comparison of the functional response and domain structure of unmodified and Sm-modified BiFeO3. At the conference he received the “Excellence award for the best oral presentation of young scientist”. In 2015, Julian Walker completed his studies and, also thanks to the results obtained during the project (3 papers, one of them published in Nature Scientific Reports), he got a position at the prestigious University of Pennstate.
E.02 International awards
COBISS.SI-ID: 27854375In the frame of the research project we investigated different designs of a ceramic resonance pressure sensor intended for high-temperature applications () 200°C). The sensor is based on a circular, edge-clamped diaphragm vibrating at its resonance frequencies. The mechanical vibration of the diaphragm is stimulated with a piezoelectric actuator whereas the resonance frequency changes due to the static deflection of the diaphragm caused by the pressure, which is the measured variable. The study includes the feasibility of materials and technology, the sensor’s properties and the thermo-mechanical aspect of the system. Three different methods for the integration of piezoelectric actuator were designed, fabricated and evaluated. The design aspect is described in the work-report.
F.06 Development of a new product
COBISS.SI-ID: 28600103In the frame of the research project we designed and constructed a measurement system based on an optical MTI 2100 displacement sensor, capable of detecting small, nanometer displacement signals from samples under electric field up to 400°C. The system consists of an optical displacement sensor, a furnace with heating elements and isolation housing, temperature sensors, sample holder, micromanipulators for electrical contacts, and the electrical instruments for the voltage application and for measurements of displacement signals (i.e., voltage generator, voltage amplifier, high-voltage probe, oscilloscope and lock-in amplifiers for detection of small (mV) voltage signals). The measurement system was successfully used during the project for the characterization of high-temperature piezoelectric properties of BiFeO3-based systems (the result is 2 published papers) and is currently used in several research projects of the department, including those with foreign institutions (prof. Jacob Jones, North Carolina State University, USA). The system will be used as a support in the development of high-temperature piezoelectrics for the company Hidria AET and within the collaboration with Thales Australia.
F.17 Transfer of existing technologies, know-how, methods and procedures into practice
COBISS.SI-ID: 28588327