Impact of Oxalate Ligand in Co-Precipitation Route on Morphological Properties and Phase Constitution of Undoped and Rh-Doped BaTiO3 Nanoparticles

Document identifier: oai:DiVA.org:ltu-77128
Access full text here:10.3390/nano9121697
Keyword: Natural Sciences, Physical Sciences, Other Physics Topics, Naturvetenskap, Fysik, Annan fysik, Rh-doped BaTiO3, Nanoparticles, Synthesis route, Co-precipitation, Perovskite, Experimentell fysik, Experimental Physics
Publication year: 2019
Relevant Sustainable Development Goals (SDGs):
SDG 9 Industry, innovation and infrastructure
The SDG label(s) above have been assigned by OSDG.ai

Abstract:

In order to design and tailor materials for a specific application like gas sensors, the synthesis route is of great importance. Undoped and rhodium-doped barium titanate powders were successfully synthesized by two routes; oxalate route and classic route (a modified conventional route where solid-state reactions and thermal evaporation induced precipitation takes place). Both powders were calcined at different temperatures. X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX) and Brunauer-Emmet-Teller (BET) analyses are employed to identify the phases and polymorphs, to determine the morphology, the chemical composition and the specific surface area of the synthesized materials, respectively. The so-called oxalate route yields pure BaTiO3 phase for undoped samples at 700 °C and 900 °C (containing both cubic and tetragonal structures), while the classic route-synthesized powder contains additional phases such as BaCO3, TiO2 and BaTi2O5. Samples of both synthesis routes prepared by the addition of Rh contain no metallic or oxide phase of rhodium. Instead, it was observed that Ti was substituted by Rh at temperatures 700 °C and 900 °C and there was some change in the composition of BaTiO3 polymorph (increase of tetragonal structure). Heat-treatments above these temperatures show that rhodium saturates out of the perovskite lattice at 1000 °C, yielding other secondary phases such as Ba3RhTi2O9 behind. Well-defined and less agglomerated spherical nanoparticles are obtained by the oxalic route, while the classic route yields particles with an undefined morphology forming very large block-like agglomerates. The surface area of the synthesized materials is higher with the oxalate route than with the classic route (4 times at 900 °C). The presence of the oxalate ligand with its steric hindrance that promotes the uniform distribution and the homogeneity of reactants could be responsible for the great difference observed between the powders prepared by two preparation routes.

Authors

Roussin Lontio Fomekong

Department of High-Temperature and Functional Coatings, Institute of Materials Research, German Aerospace Center, Cologne, Germany
Other publications >>

Shujie You

Luleå tekniska universitet; Materialvetenskap
Other publications >>

Francesco Enrichi

Luleå tekniska universitet; Materialvetenskap; Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, Italy
Other publications >>

Alberto Vomiero

Luleå tekniska universitet; Materialvetenskap; Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, Italy
Other publications >>

Bilge Saruhan

Department of High-Temperature and Functional Coatings, Institute of Materials Research, German Aerospace Center, Cologne, Germany
Other publications >>

Record metadata

Click to view metadata