TY - JOUR
T1 - Formation of complex alkoxides to control layer structure in Sr-Bi-M-O (M
T2 - Ta or Nb) perovskite thin films
AU - Kato, K.
AU - Zheng, C.
AU - Finder, J. M.
AU - Dey, Sandwip
AU - Torii, Y.
N1 - Funding Information:
S. K. Dey acknowledges the National Science Foundation (DMR) for the financial support in carrying out this investigation. The authors would like to thank Dr Nieman for his helpful discussions on NMR data, and Dr Yates for her helpful discussions on XRD data.
PY - 1998/12
Y1 - 1998/12
N2 - Precursors for layer-structured perovskite thin films of Sr2Bi2Ta3O12.5 or SBT223 and Sr2Bi2Nb3O12.5 or SBN223 were prepared by the reactions of Sr-Bi (2:2) double methoxyethoxide and Ta or Nb methoxyethoxide, followed by partial hydrolysis. By several analytical techniques, such as 1H-, 13C- and 93Nb-NMR (nuclear magnetic resonance) and FT-IR (Fourier transform infrared) the molecular structure of the precursors was found to be similar to the layer-structured perovskite crystal sub-lattice. As a result, the onset of crystallization in the sol-gel derived SBT223 thin films was at a low temperature of 550 °C. By rapid thermal annealing in an oxygen atmosphere, the single-phase perovskite films exhibited preferred (1 1 7) orientation. In contrast to the SBT system, the observed number of the pseudo-perovskite layers of TaO6 octahedral units between Bi2O2 2+ layers in the SBT223 was three. Despite the elongation of the unit cell along the c-axis, 700 °C-heated SBT223 thin film did not exhibit a saturated hysteresis loop due to the small crystallite size.
AB - Precursors for layer-structured perovskite thin films of Sr2Bi2Ta3O12.5 or SBT223 and Sr2Bi2Nb3O12.5 or SBN223 were prepared by the reactions of Sr-Bi (2:2) double methoxyethoxide and Ta or Nb methoxyethoxide, followed by partial hydrolysis. By several analytical techniques, such as 1H-, 13C- and 93Nb-NMR (nuclear magnetic resonance) and FT-IR (Fourier transform infrared) the molecular structure of the precursors was found to be similar to the layer-structured perovskite crystal sub-lattice. As a result, the onset of crystallization in the sol-gel derived SBT223 thin films was at a low temperature of 550 °C. By rapid thermal annealing in an oxygen atmosphere, the single-phase perovskite films exhibited preferred (1 1 7) orientation. In contrast to the SBT system, the observed number of the pseudo-perovskite layers of TaO6 octahedral units between Bi2O2 2+ layers in the SBT223 was three. Despite the elongation of the unit cell along the c-axis, 700 °C-heated SBT223 thin film did not exhibit a saturated hysteresis loop due to the small crystallite size.
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U2 - 10.1023/A:1008906209683
DO - 10.1023/A:1008906209683
M3 - Article
AN - SCOPUS:0032281519
SN - 0957-4522
VL - 9
SP - 457
EP - 464
JO - Journal of Materials Science: Materials in Electronics
JF - Journal of Materials Science: Materials in Electronics
IS - 6
ER -