Alkaline earth stannates have recently become important materials in ceramic technology due to its application as humidity sensor. In this work, alkaline earth stannates doped with Fe3+ were synthesized by the polymeric precursor method, with calcination at 300 °C/7 h and between 400 and 1100 °C/4 h. The powder precursors were characterized by TG/DTA after partial elimination of carbon. Characterization after the second calcination step was done by X-ray diffraction, infrared spectroscopy, and UV–vis spectroscopy. Results confirmed the formation of the SrSnO3:Fe with orthorhombic perovskite structure, besides SrCO3 as secondary phase. Crystallization occurred at 600 °C, being much lower than the crystallization temperature of perovskites synthesized by solid state reaction. The analysis of TG curves indicated that the phase crystallization was preceded by two thermal decomposition steps. Carbonate elimination occurred at two different temperatures, around 800 °C and above 1000 °C.
1. Souza, SC, Alves, MCF, Oliveira, ALM, Longo, E, Vieira, FTG, Gomes, RM, Soledade, LEB, Souza, AG, Santos, IMG. SrSnO3:Nd obtained by the polymeric precursor method. J Therm Anal Calorim. 2009;97:85–190. .
2. Tejuca, LG, Fierro, LG. Properties and applications of perovskite-type oxides. New York: Marcel Pekker INC; 1993.
3. Alves, MCF, Souza, SC, Silva, MRS, Paris, EC, Lima, SJG, Gomes, RM, Longo, E, Souza, AG, Santos, IMG. Thermal analysis applied in the crystallization study of SrSnO3. J Therm Anal Calorim. 2009;97:179–183. .
4. Kim, MG, Cho, HS, Yo, CH. Fe K-edg X-ray absorption (XANES/EXAFS) spectroscopic study of the nonstoichiometric SrFe1-xSnxO3-x system. J Phys Chem Solids. 1998;59:1369–1381. .
5. Roh, KS, Ryu, KH, Yo, CH. Nonstoichiometric and physical properties of the SrSn1-xFexO3-x system. J Solid State Chem. 1999;142:288–293. .
6. Beurmann, PS, Thangadurai, V, Weppner, W. Phase transitions in the SrSnO3–SrSnO3 solid solutions: X-ray diffraction and Mössbauer studies. J Solid State Chem. 2003;174:392–402. .
7. Alves, MCF, Souza, SC, Lima, SJG, Longo, E, Souza, AG, Santos, IMG. Influence of the precursor salts in the synthesis of CaSnO3 by the polymeric precursor method. J Therm Anal Calorim. 2007;87:763–766. .
8. Dondi, M, Cruciani, G, Guarini, G, Matteuci, F, Raimondo, M. The role of counterions (Mo, Nb, Sb, W) in Cr, Mn, Ni and V doped rutile ceramic pigments Part 2. Colour and technological properties. Ceram Int. 2006;32:393–405. .
9. Dondi, M, Matteucci, F, Cruciani, G. Zirconium titanate ceramic pigments: crystal structure, optical spectroscopy and technological properties. J Solid State Chem. 2006;179:233–246. .
10. Rao, JL, Murali, A, Rao, ED. Electron paramagnetic resonance and optical spectra of Fe(III) ions in alkali zinc borosulphate glasses. J Non Cryst Solids. 1996;202:215–221. .
11. Reddy, KN, Reddy, GS, Reddy, SL, Roo, PS. Optical absorption and EPR spectral studies of vauquelinite. Cryst Res Technnol. 2006;41:818–821. .
12. Taran, NM, Langer, K. Electronic absorption spectra of Fe3+ in andradite and epidote at different temperatures and pressures. Eur J Mineral. 2000;12:7–15.
13. Nyquist, R, Kagel, R. Infrared spectra of inorganic compounds. London: Academic Press; 1971.
14. Perry, CH, Mccarthy, DJ, Rupprecht, G. Dieletric dispersion of some perovskite zirconates. Phys Rev. 1965;138:1537–1538. .
15. Karlsson, M, Matic, A, Knee, CS, Ahmed, I, Eriksson, SG, Borjesson, L. Short-Range structure of proton-conducting perovskite BaInxZr1-xO3-x/2 (x = 0–0.75). Chem Mater. 2008;20:3480–3486. .