Laser technology to grow oxide thermoelectric materials
Nuno M. Ferreira
University of Aveiro, Portugal
: Res J Opt Photonics
Abstract
In the last years, laser technology had great developments, becoming an easy handling processing technique with decreased environmental impact and maintenance requirements. Particularly, current industrial-grade lasers show high-performance in the local modification of the surface properties of materials. Particular emphasis is given to Laser Floating Zone (LFZ) processing, allowing unique opportunities for tuning the structural, microstructural, electric and magnetic properties of bulk materials. This technique allows the growth of fully dense fibres, as well as the formation of metastable phases and/or promoting different oxidation states by adjusting the growth conditions. The results demonstrate some guidelines for tuning the phase composition and microstructure by adjusting the growth conditions. The results show also the effect on charge carriers and magnetic moment, produced due different effects in the phases formed and thus the performance of the samples, which allows a potential phase tuning of these materials. The obtained guidelines suggest that LFZ is a suitable technique for processing thermoelectric oxides, if optimized control over growth parameters and re-equilibration conditions is imposed, for device applications.
Biography
Nuno M. Ferreira, is a researcher at i3N, Physics Department at University of Aveiro, Portugal. He had participated in several R&D projects on material science. He has experience researcher in the study and development of ceramics-based materials, prepared through conventional methods (melting, solid stated), with a particular focus on laser processing materials (crystal growth – LFZ and surface sintering/modification). Present sample preparation and characterization skills include various techniques such as electrical conductivity and magnetic properties of various oxide materials. Current focus oxide materials: thermoelectrics, ferroelectrics and glass matrices doped with transition metals and rare earth for energy harvesting (conversion, transport and storage) applications. Main expertise is related to structural, magnetic and electrical properties of oxide materials prepared by laser processing.
