Piezo-generated charge mapping revealed through Direct Piezoelectric Force Microscopy

While piezoelectrics and ferroelectrics are playing a key role in many everyday applications, there are still a number of open questions related to the physics of those materials. In order to foster the understanding of piezoelectrics and ferroelectric and pave the way to future applications, the nanoscale characterization of these materials is essential. In this light, we have developed a novel AFM based mode that obtains a direct quantitative analysis of the piezoelectric coefficient d33. This nanoscale tool is capable of detecting and reveal piezo-charge generation through the direct piezoelectric effect at the surface of the piezoelectric and ferroelectric materials. We report the first nanoscale images of the charge generated in a thick single crystal of Periodically Poled Lithium Niobate (PPLN) and a Bismuth Ferrite (BiFO3) thin film by applying a force and recording the current produced by the materials. The quantification of both d33 coefficients for PPLN and BFO are 13 +- 2 pC/N and 46 +- 7 pC/N respectively, in agreement with the values reported in the literature. This new mode can operate simultaneously with PFM mode providing a powerful tool for the electromechanical and piezo-charge generation characterization of ferroelectric and piezoelectric materials

Integration of functional complex oxide nanomaterials on silicon

The combination of standard wafer-scale semiconductor processing with the properties of functional oxides opens up to innovative and more efficient devices with high value applications which can be produced at large scale. This review uncovers the main strategies that are successfully used to monolithically integrate functional complex oxide thin films and nanostructures on silicon: the chemical solution deposition approach (CSD) and the advanced physical vapor deposition techniques such as oxide molecular beam epitaxy (MBE). Special emphasis will be placed on complex oxide nanostructures epitaxially grown on silicon using the combination of CSD and MBE. Several examples will be presented, with a particular stress on the control of interfaces and crystallization mechanisms on epitaxial perovskite oxide thin films, nanostructured quartz thin films, and octahedral molecular sieve nanowires. This review enlightens on the potential of complex oxide nanostructures and the combination of both chemical and physical elaboration techniques for novel oxide-based integrated devicesAC acknowledges the financial support from 1D-RENOX project (Cellule Energie INSIS-CNRS). J.M.V.-F. also acknowledges MINECO for support with a Ph.D. grant of the FPI program. We thank David Montero and L. Picas for technical support. We also thank P. Regreny, C. Botella, J.B. Goure for technical assistance on the Nanolyon technological platform. We acknowledge MICINN (MAT2008-01022 MAT2011-28874-c02-01 and MAT2012-35324), Consolider NANOSELECT (CSD2007-00041), Generalitat de Catalunya (2009 SGR 770 and Xarmae), and EU (HIPERCHEM, NMP4-CT2005-516858) projects. The HAADF-STEM microscopy work was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. This research was supported by the European Research Council (ERC StG-2DTHERMS), Ministerio de Economía y Competitividad of Spain (MAT2013-44673-R) and EU funding Project “TIPS” Thermally Integrated Smart Photonics Systems Ref: 644453 call H2020-ICT-2014-1S

Epsilon-Fe 2 O 3 Nanocrystals inside Mesoporous Silicas with Tailored Morphologies of Rod, Platelet and Donut

International audienc

The Opportunity Cost and OCBA Selection Procedures in Ordinal Optimization

International audienc

Water-Induced Phase Separation Forming Macrostructured Epitaxial Quartz Films on Silicon

International audienceQuartz has been widely used as a bulk material in optics, the microelectronic industry, and sensors. The nanostructuring and direct integration of oriented quartz crystals onto a semiconductor platform has proven to be challenging. However, here, a new approach is presented to integrate epitaxial quartz films with macroperforations within the range of 500 nm and 1 mu m using chemical solution deposition. This method constitutes an appealing approach to develop piezoelectric mass sensors with enhanced resonance frequencies due to the thickness reduction. Perforated quartz films on (100)-silicon are prepared from amorphous silica films deposited via dip-coating and doped with metal cations that catalyze quartz crystallization. The metal cations are also active in the formation of the macroperforations, which arise due to a phase separation mechanism. Cationic surfactant-anion-metal cation assemblies stabilize droplets of water, creating an indentation in the hydrophilic silica matrix which remains after solvent evaporation. Many cations induce phase separation, including Li+, Na+, Sr2+, Mn2+, Fe2+/Fe3+, Ca2+, Ce3+ and La3+ but only the Sr2+ and Ca2+ cations in this series induce the epitaxial growth of alpha-quartz films under the conditions studied. The combination of sol-gel chemistry and epitaxial growth opens new opportunities for the integration of patterned quartz on silicon

Charge transport and electrochemical properties of colloidal greigite (Fe3S4) nanoplatelets

Room-temperature superparamagnetic greigite nanoplatelets were synthesized using 3-methyl catechol as growth moderator and phase-control agent, in the presence of sulfur, thiosulfate, octadecylamine, and Fe2+. Dense films of nanoplatelets showed ohmic behavior in the 10–300 K range. In as-deposited films the resistivity increased with decreasing temperature (as for semiconductors), while in hydrazine-treated films it decreased with decreasing temperature, as for metals. The electrochemical properties of as-prepared greigite nanoplatelets upon lithiation/de-lithiation have been followed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrodes containing greigite nanoplatelets were found to be active in the lithiation/delithiation processes

Charge Transport and Electrochemical Properties of Colloidal Greigite (Fe(3)S(4)) Nanoplatelets

Room-temperature superparamagnetic greigite nanoplatelets were synthesized using 3-methyl catechol as growth moderator and phase-control agent, in the presence of sulfur, thiosulfate, octadecylamine, and Fe(2+). Dense films of nanoplatelets showed ohmic behavior in the 10-300 K range. In as-deposited films the resistivity increased with decreasing temperature (as for semiconductors), while in hydrazine-treated films it decreased with decreasing temperature, as for metals. The electrochemical properties of as-prepared greigite nanoplatelets upon lithiation/de-lithiation have been followed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrodes containing greigite nanoplatelets were found to be active in the lithiation/delithiation processes