Structural, morphological, and optical investigations of Mn-doped LaAlO3 perovskite obtained by microwave-assisted combustion and rapid calcination at low temperature.
DIAS, Luís Paulo da Silva; OLIVEIRA, Jefferson Santos; MARQUES, Gleison Neres; ARAÚJO, Tomaz Rodrigues de; MELO, Dulce Maria de Araújo; JUNIOR, Aluisio Alves Cabral; VASCONCELOS, Jomar Sales; RANGEL, José Hilton Gomes; BERNARDI, Maria Inês Basso; FIGUEREDO, Gilvan Pereira de.
DIAS, Luís Paulo da Silva; OLIVEIRA, Jefferson Santos; MARQUES, Gleison Neres; ARAÚJO, Tomaz Rodrigues de; MELO, Dulce Maria de Araújo; JUNIOR, Aluisio Alves Cabral; VASCONCELOS, Jomar Sales; RANGEL, José Hilton Gomes; BERNARDI, Maria Inês Basso; FIGUEREDO, Gilvan Pereira de.
Abstract: In this work, LaAlO3 perovskite was doped with 1, 2, 3, 5, 8, and 13 mol% of Mn using the microwave-assisted combustion method. The powders produced were heat treated at 700 °C and 900 °C for 10 min in an adapted microwave oven and then characterized by Thermogravimetric analysis (TG/DTG) and Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD) and Rietveld refinement, X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared Spectroscopy (FTIR), Raman, Ultraviolet?Visible Reflectance (UV?Vis), Field Emission Scanning Electron Microscopy (FE-SEM) and Energy Dispersive X-ray Spectroscopy (EDS). The materials produced doped with the highest concentration of Mn (13 %) showed a single-phase reduced crystallite size compared to the pure sample. The unit cell volumes increased compared to the pure material, while the oxidation state of the dopant was mainly Mn3+. The refinement data for the volume of the different polyhedral that comprise the LaAlO3 unit cell revealed a local change at both sites, which may also indicate Mn substitution at the A site. The heat treatment temperature did not change significantly, demonstrating the method's efficiency in producing perovskites at temperatures and times below those reported in the literature. The morphology observed was porous and irregular agglomerates, and the bandgap was 2.90 eV.
@article={003207203,author = {DIAS, Luís Paulo da Silva; OLIVEIRA, Jefferson Santos; MARQUES, Gleison Neres; ARAÚJO, Tomaz Rodrigues de; MELO, Dulce Maria de Araújo; JUNIOR, Aluisio Alves Cabral; VASCONCELOS, Jomar Sales; RANGEL, José Hilton Gomes; BERNARDI, Maria Inês Basso; FIGUEREDO, Gilvan Pereira de.},title={Structural, morphological, and optical investigations of Mn-doped LaAlO3 perovskite obtained by microwave-assisted combustion and rapid calcination at low temperature},journal={Materials Chemistry and Physics},note={v. 325, p. 129767-1-129767-13},year={2024}}