3rd International Conference on Nanomaterials Science and Mechanical Engineering: book of abstracts

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Direct Measurement of Piezoelectric Response around Ferroelectric Domain Walls in Crystals with Engineered Domain Configuration

We report the first investigation of the piezoelectric response on a nanoscale in the poled ferroelectric crystals with engineered configuration of domains. Piezoresponse force microscopy of tetragonal 0.63PMN-0.37PT relaxor-based ferroelectric crystals reviled that the d33 piezoelectric coefficient is significantly reduced within the distance of about 1 um from the uncharged engineered domain wall. This finding is essential for understanding the mechanisms of the giant piezoresponse in relaxor-based crystals and for designing new piezoelectric materials

Thermal vapor sulfurization of molybdenum layers

Sulfurization of molybdenum layers is a promising route for obtaining large-scale and high-quality transition metal dichalcogenides. Here we describe the synthesis of continuous and homogeneous MoS2 in the centimeter scale by the thermal vapor sulfurization of pre-deposited molybdenum precursors on SiO2. Metallic molybdenum as well as MoO3 were used as precursors while the sulfurization was performed by chemical vapor deposition. A multi-technique characterization was employed to fully describe the deposition of molybdenum as well as its sulfurization. Thus, Raman spectroscopy, X-ray and ultra-violet photoelectron spectroscopies as well as scanning electron and atomic force microscopies indicated that the molybdenum layers were completely transformed in MoS2. The samples were homogeneous in the centimeter scale and quite flat with a root mean square roughness of 1.4 Å. Furthermore, its work function was 4.1 eV.publishe

5th International Conference on Nanomaterials Science and Mechanical Engineering

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Domain Dynamics in Piezoresponse Force Microscopy: Quantitative Deconvolution and Hysteresis Loop Fine Structure

Domain dynamics in the Piezoresponse Force Spectroscopy (PFS) experiment is studied using the combination of local hysteresis loop acquisition with simultaneous domain imaging. The analytical theory for PFS signal from domain of arbitrary cross-section is developed and used for the analysis of experimental data on Pb(Zr,Ti)O3 polycrystalline films. The results suggest formation of oblate domain at early stage of the domain nucleation and growth, consistent with efficient screening of depolarization field within the material. The fine structure of the hysteresis loop is shown to be related to the observed jumps in the domain geometry during domain wall propagation (nanoscale Barkhausen jumps), indicative of strong domain-defect interactions.Comment: 17 pages, 3 figures, 2 Appendices, to be submmited to Appl. Phys. Let

2nd International Conference on Nanomaterials Science and Mechanical Engineering: book of abstracts

2nd International Conference on Nanomaterials Science and Mechanical Engineering: book of abstracts - University of Aveiro, Portugal July 9-12, 2019.publishe

International Conference on Nanomaterials Science and Mechanical Engineering: book of abstracts

The conference (International Conference on Nanomaterials Science and Mechanical Engineering, University of Aveiro, Portugal, July 16-18, 2018) looks for significant Modern Problems of Nanomaterials Science and Mechanical Engineering, to provide a platform to the global researchers and practitioners from both academia as well as industry to meet and share cutting-edge development in the fields, to give possibility for young scientists and students present results and find your place in the future world.publishe

Piezoelectricidad y ferroelectricidad en biomateriales

En este artículo se presenta una revisión de los conceptos de piezoelectricidad y ferroelectricidad, así como sus aplicaciones en materiales complejos e híbridos orgánico-inorgánicos mediante el uso de las técnicas de microscopía de fuerza atómica (AFM) y de fuerza de piezorespuesta (PFM). Aunque este tipo de estudios son escasos en las áreas biológicas, se sugiere el uso de estas técnicas para analizar las propiedades de piezorespuesta en péptidos debido a su relevancia en las reacciones prebióticaspero y en el diseño de máquinas nanomoleculares.

Room temperature surface piezoelectricity in SrTiO3 ceramics via piezoresponse force microscopy

SrTiO3 ceramics are investigated by piezoresponse force microscopy. Piezoelectric contrast is observed on polished surfaces in both vertical and lateral regimes and depends on the grain orientation varying in both sign (polarization direction) and amplitude. The observed contrast is attested to the surface piezoelectricity due to flexoelectric effect (strain gradient-induced polarization) caused by the surface relaxation. The estimated flexoelectric coefficient is approximately one order of magnitude smaller as compared to those recently measured in SrTiO3 single crystals. The observed enhancement of piezoresponse signal at the grain boundaries is explained by the dipole moments associated with inhomogeneous distribution of oxygen vacancies