Thermoelectric materials investigated by X-ray dynamical diffraction

• Grant number: 19/15574-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2019
• End date: December 09, 2021
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Sérgio Luiz Morelhão
• Grantee: Maurício Bastos Estradiote
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Dynamic X-ray diffraction offers unprecedented possibilities in terms of structural resolution. 296/5000 However, the application of the technique of measuring simultaneous diffraction is limited by the need to anticipate experimental conditions that allow the resolution of the structural details relevant to the properties of the investigated systems; details that are inaccessible by conventional methods. In the study of thermoelectric materials of the class of skutterudites, initial predictions indicate triplet phases accessible through dynamic diffraction with a strong dependence of the energy of the synchrotron radiation, as well as the Debye-Waller factors. This strong dependence allows revisiting the phonon scattering mechanism in these materials, but demands in situ experiments in the function of energy and temperature. The objective of this project is to eliminate intrinsic and instrumental errors of simultaneous diffraction position measurements, and in this way to be able to establish methods of in situ calibration of temperature and energy. In addition, simple diffraction geometry (specular reflection) combined with the expected resolution of the order of 10-6 for both lattice and energy parameters determination allows many other in situ studies involving single crystals under extreme conditions and limited goniometry. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

VALERIO, ADRIANA; PENACCHIO, RAFAELA F. S.; ESTRADIOTE, MAURICIO B.; CANTARINO, MARLI R.; GARCIA, FERNANDO A.; MORELHAO, SERGIO L.; RAFTER, NIAMH; KYCIA, STEFAN W.; CALLIGARIS, GUILHERME A.; REMEDIOS, CLAUDIO M. R.. Phonon scattering mechanism in thermoelectric materials revised via resonant x-ray dynamical diffraction. MRS COMMUNICATIONS, v. 10, n. 2, p. 265-271, JUN 2020. (18/00303-7, 19/15574-9, 19/11564-9)