Periodic Reporting for period 2 - TransFerr (Transition metal oxides with metastable phases: a way towards superior ferroic properties)
Okres sprawozdawczy: 2019-12-01 do 2023-08-31
The growing market of consumer electronics and related industrial applications require a wide spectrum of cost-effective functional materials with controllable properties. Recent ecological regulations stimulate utilizing novel lead-free materials with physical parameters comparable to or exceeding commonly used lead-based piezoeletrics. Compounds based on transition metal oxides are considered as the most promising eco-friendly functional materials to be used in magnetic memory or energy storage devices, energy transfer moduli, tunable microwave resonators, phase shifters and other electronic devices and sensors. Additionally, magneto-electric coupling specific for ferrites allows to use them as energy converters and energy harvesting devices. Photovoltaic properties of BiFeO3-based materials disclose novel opportunities in solar cells designing.
Declared properties of the materials studied within the Project (complex oxides with perovskite structure) permit to improve the functionality of existing electrical devices via formation of metastable states. Tunability of the electric, magnetic, transport parameters and magnetoelectric coupling provides an effective method to enhance perspectives of practical applications where special attention is focused on the magnetic field sensors for the magnetic memory storage devices.
TransFerr Project aimed to design and study novel functional materials with multiferroic properties required in electric applications. It was focused on the two main approaches to create metastable structural states: (i) to design compounds based on novel ceramic compositions via chemical substitution and proper post-synthesis treatment, and (ii) to exploit chemical routes for the synthesis of thin films and nanoceramics.
The research permitted to design novel functional materials with pronounced and controllable physical properties. The consortium Partners increased their knowledge and skills in the area of innovative multifunctional materials through results dissemination and extensive transfer of the experience in complementary subjects.
Declared properties of the materials studied within the Project (complex oxides with perovskite structure) permit to improve the functionality of existing electrical devices via formation of metastable states. Tunability of the electric, magnetic, transport parameters and magnetoelectric coupling provides an effective method to enhance perspectives of practical applications where special attention is focused on the magnetic field sensors for the magnetic memory storage devices.
TransFerr Project aimed to design and study novel functional materials with multiferroic properties required in electric applications. It was focused on the two main approaches to create metastable structural states: (i) to design compounds based on novel ceramic compositions via chemical substitution and proper post-synthesis treatment, and (ii) to exploit chemical routes for the synthesis of thin films and nanoceramics.
The research permitted to design novel functional materials with pronounced and controllable physical properties. The consortium Partners increased their knowledge and skills in the area of innovative multifunctional materials through results dissemination and extensive transfer of the experience in complementary subjects.
Research was focused on the preparation of compounds based on complex transition metal oxides (such as bismuth ferrites or manganites) in form of nanopowders, thin films, and ceramics. The important issue was to prepare single phase materials and to perform characterization of their crystal structure depending on the preparation technique, chemical composition, and environment (temperature, electric and magnetic field, etc.). The obtained compounds were characterized in terms of their functional properties as well as the correlation between the crystal structure, morphology, and physical properties depending on the preparation methods.
Multiple series of powders, ceramics, and thin films were prepared for studies. Samples were fabricated using solid-state, sol–gel, precipitation, or combustion methods. Various techniques were used to describe their properties. Samples were attested by XRD, electron microscopy techniques, termogravimetric analysis, and spectroscopic methods. Other specific approaches were used to look at some particular features of selected samples. For example, atomic resolution scanning transmission electron microscopy was used to explore the atomic structure. Local electromechanical measurements were performed via piezoresponse force microscopy. The same technique was used to study domain structure before and after local polarization reversal caused by stress in ceramics. The conductivity was studied using a scanning probe microscopy approach at the nanoscale level. Finally, synchrotron X-ray and neutron powder diffraction measurements were used to investigate more precisely the structures.
The problem of obtaining pure phase BiFeO3-based compounds is very widely displayed in the literature. Interest to these materials is related to their unique functional properties, and especially to the changes in these properties that occur when the material's crystal structure is modified. Such changes are particularly dependent on the size of the nanocrystals, which influences the temperature of the transformations and the ways they occur.
An important issue was also upscaling because modification of synthesis condition (as higher amounts of reagents) may cause change of phase composition. Therefore, fabrication of bigger amount of compounds was also tested to show the availability to move techniques to the (pre)industrial scale.
The Project participants consolidated the knowledge about obtaining ferroic materials and investigated the influence of chemical (e.g. composition, organic matrix used in sol–gel method, and fuel type in self-combustion method) and physical (e.g. temperature and annealing time or external stimuli) factors on compound properties (particle size, crystal structure, magnetization, piezoresponse, etc.). The main research was focused on the compounds having chemical compositions near to the morphotropic phase boundary regions where an improvement of functional properties is observed.
Research conducted under the TransFerr project was broadly presented in scientific articles – 63 papers were published in journals. The articles covered all aspects of the project studies. Participants were showing the results in over 80 conference presentations. Project topic was included in workshops and lectures given to students at Universities in Vilnius, Kiev, Aveiro, Gomel, Minsk, and Herrsching. We were also present during events dedicated to the general public, such as, Lower Silesian Science Festival, Doors Open Day for Youth, or Belarusian Science Day.
Details of the project activities can be followed through the Project website: http://transferr.eu/
Multiple series of powders, ceramics, and thin films were prepared for studies. Samples were fabricated using solid-state, sol–gel, precipitation, or combustion methods. Various techniques were used to describe their properties. Samples were attested by XRD, electron microscopy techniques, termogravimetric analysis, and spectroscopic methods. Other specific approaches were used to look at some particular features of selected samples. For example, atomic resolution scanning transmission electron microscopy was used to explore the atomic structure. Local electromechanical measurements were performed via piezoresponse force microscopy. The same technique was used to study domain structure before and after local polarization reversal caused by stress in ceramics. The conductivity was studied using a scanning probe microscopy approach at the nanoscale level. Finally, synchrotron X-ray and neutron powder diffraction measurements were used to investigate more precisely the structures.
The problem of obtaining pure phase BiFeO3-based compounds is very widely displayed in the literature. Interest to these materials is related to their unique functional properties, and especially to the changes in these properties that occur when the material's crystal structure is modified. Such changes are particularly dependent on the size of the nanocrystals, which influences the temperature of the transformations and the ways they occur.
An important issue was also upscaling because modification of synthesis condition (as higher amounts of reagents) may cause change of phase composition. Therefore, fabrication of bigger amount of compounds was also tested to show the availability to move techniques to the (pre)industrial scale.
The Project participants consolidated the knowledge about obtaining ferroic materials and investigated the influence of chemical (e.g. composition, organic matrix used in sol–gel method, and fuel type in self-combustion method) and physical (e.g. temperature and annealing time or external stimuli) factors on compound properties (particle size, crystal structure, magnetization, piezoresponse, etc.). The main research was focused on the compounds having chemical compositions near to the morphotropic phase boundary regions where an improvement of functional properties is observed.
Research conducted under the TransFerr project was broadly presented in scientific articles – 63 papers were published in journals. The articles covered all aspects of the project studies. Participants were showing the results in over 80 conference presentations. Project topic was included in workshops and lectures given to students at Universities in Vilnius, Kiev, Aveiro, Gomel, Minsk, and Herrsching. We were also present during events dedicated to the general public, such as, Lower Silesian Science Festival, Doors Open Day for Youth, or Belarusian Science Day.
Details of the project activities can be followed through the Project website: http://transferr.eu/
Transferr Project allowed to successfully reach the following scientific activities:
- to synthesize the compounds (incl. bulk ceramics, films and nanopowders) according to the scientific plan as well as some additional compounds which were not planned but were justified by the scientific results;
- to find out optimal preparation conditions for the compounds based on the iron and manganese oxides having prominent and controllable physical properties, selected preparation procedures are compatible/adaptive with existing industrial requirements;
- to construct solid and reliable physical models which explain the origin of the physical properties of the compounds and can predict the chemical compositions of the materials with optimal functional properties.
Because of certain unexpected but very prominent scientific results (viz. rapid increase in polarization and magnetiс response) the project participants have considered to expand the area of the compounds to be study and decided to prepare composites based on ferrite and alkali halides; these unplanned preparation and measurements procedures will assist to clarify the magnetization changes happened in the upper layer of the ferrite grains because of redox reactions occurred at the interface ferrite - alkali halide.
The obtained and planned results of the Project will definitely improve the knowledge in the area of tunable functional materials based on complex oxide systems; the already built and expanding network of scientific and social contacts will contribute to a creation of knowledge-based society which is highly important for young researchers for their career development and perspectives.
- to synthesize the compounds (incl. bulk ceramics, films and nanopowders) according to the scientific plan as well as some additional compounds which were not planned but were justified by the scientific results;
- to find out optimal preparation conditions for the compounds based on the iron and manganese oxides having prominent and controllable physical properties, selected preparation procedures are compatible/adaptive with existing industrial requirements;
- to construct solid and reliable physical models which explain the origin of the physical properties of the compounds and can predict the chemical compositions of the materials with optimal functional properties.
Because of certain unexpected but very prominent scientific results (viz. rapid increase in polarization and magnetiс response) the project participants have considered to expand the area of the compounds to be study and decided to prepare composites based on ferrite and alkali halides; these unplanned preparation and measurements procedures will assist to clarify the magnetization changes happened in the upper layer of the ferrite grains because of redox reactions occurred at the interface ferrite - alkali halide.
The obtained and planned results of the Project will definitely improve the knowledge in the area of tunable functional materials based on complex oxide systems; the already built and expanding network of scientific and social contacts will contribute to a creation of knowledge-based society which is highly important for young researchers for their career development and perspectives.