, Pechini method (also known as the citrate route or polymericprecursormethod) has been widely reported for the synthesis of many oxide powders [ 20 – 24 ].
Invented by Pechini [ 25 ], this process involves a polyester-type resin formation which
Authors:Soraia de Souza, Mary Alves, A. de Oliveira, E. Longo, F. Ticiano Gomes Vieira, Rodinei Gomes, L. Soledade, A. de Souza, and Iêda Garcia dos Santos
In this work, the synthesis of Nd-doped SrSnO3 by the polymeric precursor method, with calcination between 250 and 700 °C is reported. The powder precursors were characterized
by TG/DTA and high temperature X-ray diffraction (HTXRD). After heat treatment, the material was characterized by XRD and
infrared spectroscopy. Ester and carbonate amounts were strictly related to Nd-doping. According to XRD patterns, the orthorhombic
perovskite was obtained at 700 °C for SrSnO3 and SrSn0.99Nd0.01O3. For Sr0.99Nd0.01SnO3, the kinetics displayed an important hole in the crystallization process, as no peak was observed in HTXRD up to 700 °C,
while a XRD patterns showed a crystalline material after calcination at 250 °C.
Authors:Mary Alves, Soraia Souza, S. Lima, E. Longo, A. Souza, and Iêda Santos
CaSnO3 was synthesized by the polymeric precursor
method, using different precursor salts as (CH3COO)2CaH2O,
CaCl22H2O and CaCO3,
leading to different results. Powder precursor was characterized using thermal
analysis. Depending on the precursor different thermal behaviors were obtained.
Results also indicate the formation of carbonates, confirmed by IR spectra.
After calcination and characterization by XRD, the formation of perovskite
as single phase was only identified when calcium acetate was used as precursor.
For other precursors, tin oxide was observed as secondary phase.
Authors:Fabiane de Jesus, Ronaldo Silva, and Zélia Macedo
Bismuth germanate ceramic powders were synthesized for the first time by the polymeric precursor method (Pechini’s method).
Differential thermal analysis and thermogravimetric techniques were used to study the decomposition of the resin precursor,
which indicated a suitable calcination temperature at 600 °C. It was observed that the mass loss occurs in two main stages
that are associated with two exothermic reactions. The crystalline phases of the powders were inspected by the X-ray diffraction
technique after thermal treatment between 300 and 600 °C. Single phase Bi4Ge3O12 ceramic bodies were obtained after sintering at 840 °C for 10 h. The sintered ceramics presented a luminescence band emission
centred at around 530 nm when excited with X-rays and UV radiation.
Authors:Danniely de Melo, M. Santos, Iêda Santos, L. Soledade, M. Bernardi, E. Longo, and A. Souza
materials are used as sensors, catalysts and in electro–optical devices.
This work aims to synthesize and characterize the SnO2/Sb2O3-based
inorganic pigments, obtained by the polymeric precursor method, also known
as Pechini method (based on the metallic citrate polymerization by means of
ethylene glycol). The precursors were characterized by thermogravimetry (TG)
and differential thermal analysis (DTA). After characterization, the precursors
were heat-treated at different temperatures and characterized by X-ray diffraction.
According to the TG/DTA curves basically two-step mass loss process was observed:
the first one is related to the dehydration of the system; and the second
one is representative to the combustion of the organic matter. Increase of
the heat treatment temperature from 500 to 600C and 700C resulted
higher crystallinity of the formed product.
Authors:L. da Silva, M. Bernardi, L. Maia, G. Frigo, and V. Mastelaro
This work reports on the synthesis of a SrTi1−xFexO3 nanostructured compound (0.0 ≤ x ≤ 0.1) using a modified polymeric precursor method. The effect of the addition of iron on the thermal, structural and morphological
properties of the nanoparticles was investigated by FT-IR spectroscopy, X-ray diffraction, and field emission scanning electron
microscopy (FE-SEM). A thermogravimetric analysis indicated that the crystallization process preceded by three decomposition
steps. Differential thermal analysis experiments showed that decomposition occurred in a broad range of temperatures from
400 to 600 °C. It was observed that iron ions acted as catalysts, promoting rapid organic decomposition and phase formation
at a lower temperature than in SrTiO3. Moreover, the addition of iron decreased the crystallite size and increased the lattice parameter of the SrTi1−xFexO3 structure.