Abstract:

The combination of several experimental techniques and the microstructural modeling including the volume-weighted diameter size, surface-weighted ’true’ crystallite size for an ellipsoidal domain shape as well as the Debye Function (DFA) overcome conventional methods of analysis (notably the Rietveld method) that fail to consider important information contained in diffuse scattering, typically of disordered and/or nanometric materials.

This seminar is devoted to show some results on these modeling for the Fe56Te44 and CoxTe100-x (with x = 32, 34 and 40) samples. Moreover, a brief overview on a novel electrochemical sensors based on carbon paste electrodes (CPE) will be delivered. For instance, (CPE)/Ni3-xTe2 applied for the simultaneous detection of the neurotransmitters dopamine (DA) and adrenaline (AD) in phosphate buffer solution (pH 7.0), a CPE/NiTe2 successfully applied to morin determination in high, medium, and low polyphenols content red wines such as Tannat, Cabernet Sauvignon, and Pinot Noir, as well as the γ-CoTe2 nanocrystals (γ-CoTe2/GCE) with outstanding sensing abilities for ferulic acid. All the Iron, Nickel and Cobalt Telluride composites were prepared by mechanochemical route in just a few hours and carefully characterized by X-ray diffraction, calorimetry, transmission electron microscopy, Raman spectroscopy, and magnetometry techniques.

At the end of the presentation few perspectives of complementary characterization using neutrons and synchrotron will be presented with focus on thermoelectric materials.

Bio:

Carlos E. M. Campos is Full Professor in the Department of Physics at the Federal University of Santa Catarina (UFSC) in Brazil. Holds his Ph.D. in Experimental Physics at UFSC (2005), with a period at the Université Pierre et Marie Curie (Paris VI) in France when started studying physical properties and phase transitions at high pressures generated by diamond anvil cells (DAC). He has experience in Mechanochemical Synthesis (MS) of chalcogenide Nanomaterials, X-ray Powder Diffraction (XRPD), calorimetry (DSC, DTA-TGA), X-ray absorption (XAS), electron microscopy and Raman scattering. His most recent scientific interests are: i) in-situ and in-operando characterization of nanomaterials produced by MS and their applications in electroanalytics, catalysis, thermoelectrics, etc.; and ii) quantitative phase analysis of cementitious materials even under hydration conditions using XRPD data from conventional and synchrotron sources. Profile page at the university: https://pcemc.paginas.ufsc.br