We review our recent works on the visualization of chemical bonding and diffusional pathway of mobile ions of advanced ceramic materials through advanced analytical techniques including synchrotron X-ray and neutron powder diffraction experiments. The results are supported by density functional theory (DFT) based electronic calculations and bond valence method. Covalent bonding between a cation and an anion was observed in maximum-entropy method (MEM) electron-density distribution of visible-light responsive photocatalysts BaTaO2N, LaTiO2N, GaN-ZnO, TaON and Sm2Ti2S2O5. The covalent bonding makes the valence band width wider leading to a narrower band gap, which is responsible for the visible-light response of these materials. Covalent bonding and charge transfer of Si-N bonds in α-Si3N4 were visualized in its MEM electron-density distribution. Zr-O covalent bonds were also observed in MEM electron-density distribution of nano-sized (11 nm) zirconium oxide powders. Crystal structure and oxide-ion diffusion paths of nano-sized (10 nm) ceria-zirconia powders were examined as a function of temperature. Defect and distorted fluorite-type materials such as Ce0.5Zr0.5O2, CeO2, CeO2-Y2O3, Bi2O3-Yb2O3 and CuI exhibit <111> anisotropic motion and <100> diffusion paths of mobile ions. We also visualized the ion diffusion pathways in perovskite-type oxides, perovskite related materials and apatite-type oxides.
4:30pm - 5:00pm Invited
Self-Assembly of C3 Symmetric Macrocycles into Very Polar and Porous Crystals
Thomas MARMIN1, Pierre BAILLARGEON2, Sylvain BERNARD1, Yves DORY1
1Université de Sherbrooke, Canada; 2CEGEP de Sherbrooke, Canada
We present here how we have succeeded in synthesizing cyclic peptides of a novel genus and presenting strong dipoles. By a hierarchical process, we have been able to transfer the dipole of the monomers to the infinite nanotubes of which they are composed. We have even continued this phenomenon of amplification of the dipoles to monocrystals, in principle ferroelectric.
5:00pm - 5:30pm Invited
Nanostructured Quantum Resistive Sensors (QRS) made of Polymer Functionalized Nanocarbon Architectures for Health Monitoring
Jean-Francois FELLER, Mickaël CASTRO
Smart Plastics Group, Bretagne Loire University (UBL), France
During the last decade, several nanocarbon species such as nanoparticles (CNP), nanotubes (CNT) or nanofoils (GR) have been synthesized allowing to design new functional conductive polymer nanocomposite (CPC) films able to react to their environment. In particular nanocarbon based hierarchical conducting architectures can lead to quantum resistive sensors (QRS) able to detect tiny variations of strain  or volatile organic compounds VOC concentrations , thanks to respectively their original piezo- and chemo-resistive properties. When properly structured from the nano- to the macro-scale, these nanohybrids can meet promising applications such as structural health monitoring in composite materials (SHM) or human health monitoring by the non-invasive diagnosis of diseases derived from the analysis of VOC biomarkers emitted by the body (volatolomics). The best strategies used to control the different types of conductive architectures during their fabrication, and in particular the tailoring of the nano-junctions responsible for QRS sensitivity will be presented and discussed.
 T.T. Tung, C. Robert, M. Castro, J.F. Feller, T.Y. Kim, K.S. Suh, Enhancing the sensitivity of graphene/polyurethane nanocomposite flexible piezo-resistive pressure sensors with magnetite nano-spacers, Carbon N. Y. 108 (2016) 450–460.
 S. Nag, M. Castro, V. Choudhary, J.F. Feller, Sulfonated poly(ether ether ketone) [SPEEK] nanocomposites based on hybrid nanocarbons for the detection and discrimination of some lung cancer VOC biomarkers, J. Mater. Chem. B Biol. Med. 5 (2017) 348–359.
5:30pm - 6:00pm Invited
Charge Transport-Related Phenomena in Ferroelectrics: Resistive Switching and Photovoltaic Effect
1South China Normal University, China; 2Nanjing University, China
The switchable polarization endows the ferroelectric materials with a wide range of tunable properties, for example, the resistive switching and photovoltaic properties. This provides a unique opportunity to obtain novel multifunctionalities in ferroelectric capacitors.
Here, using a polystyrene spheres template method, we develop well-ordered Au nanoelectrode arrays on super-tetragonal BiFeO3 (T-BFO)/La0.7Sr0.3MnO3 (LSMO) epitaxial thin films, forming the Au/T-BFO/LSMO nanocapacitors. The nanocapacitors exhibit tunable resistance states and photovoltaic properties, as controlled by the ferroelectric polarization of T-BFO. Thanks to the giant polarization of T-BFO, both a giant electroresistance (ON/OFF current ratio > 20000) and a noticeable photovoltage (~0.4 V) are achieved in the Au/T-BFO/LSMO nanocapacitors. These results demonstrate that the T-BFO-based nanocapacitors are promising for applications in high-density memories with multiple routes for non-destructive readout, as well as other multifunctional nanodevices.
The resistive switching in ferroelectric diodes often shows poor reproducibility and reliability, whose origin has been specifically studied here. By means of scanning Kelvin probe microscopy we show that the electrical poling of ferroelectric diodes can cause significant charge injection and trapping besides polarization switching. We further show that the reproducibility and stability of switchable diode-type RS behavior are significantly affected by the interfacial traps. A theoretical model is then proposed to quantitatively describe the modifications of Schottky barriers by the charge injection and trapping. This model is able to reproduce various types of hysteretic current-voltage characteristics as experimentally observed. It is further revealed that the charge injection and trapping can significantly modify the electroresistance ratio, RS polarity, and high-/low-resistance states initially defined by the polarization direction.
6:00pm - 6:15pm Oral
An Experimental Study on Low-Energy Impact Adsorption Performance of BaTiO3-ZrO2 Composite
Laura Katariina TIAINEN1, Sara MADEIRA1, Filipe Samuel SILVA1, Michael GASIK2
1University Of Minho, Portugal; 2Aalto University, Finland
Material’s capability to adsorb impacts has importance in numerous of applications. Particularly ceramics are known to be brittle and prone to cracking, which is seen in dental applications and in jewellery for instance. This study presents experimental work on the production of a piezoelectric ceramic composite and evaluates briefly their applicability of piezoelectric effect in the above-mentioned applications. The bulk properties of the specimen made of nano-size barium titanate (BaTiO3) particles and zirconia (ZrO2) powder are compared with pure zirconia by dynamic mechanical analysis (DMA). The specimens are produced by pressing and sintering. Prior the DMA the samples’ morphology and crystallinity are characterised by SEM, CT-scanning and x-ray diffraction. Samples of made of bulk zirconia, non-poled composite and poled composite is measured by DMA, ballistometry and Hopkinson method.