TY - JOUR
T1 - A simple solution route to the synthesis of pure La2Ti2O7 and Nd2Ti2O7 at 700-800°C by polymerized complex method
AU - Milanova, Maria M.
AU - Kakihana, Masato
AU - Arima, Momoko
AU - Yashima, Masatomo
AU - Yoshimura, Masahiro
N1 - Funding Information:
This is supported by the disappearance of a characteristic peak of pure titanium tetraisopropoxide at 79 ppm. We concentrated our attention on the 74-94 ppm region, where resonances associated with alcoholic carbons (78 ppm) in CA (or in esterificated CA) occur \[27\],t he position of which is marked by * \[26\]:
PY - 1996/9/15
Y1 - 1996/9/15
N2 - A polymerized complex technique was utilized to prepare high-purity La2Ti2O7 and Nd2Ti2O7. Heating of mixed solutions of citric acid (CA), ethylene glycol (EG), La (or Nd) and Ti ions with a molar ratio of CA:EG:La(or Nd):Ti = 5:20:1:1 at 130°C produced a yellowish transparent polymeric gel without any precipitation, which was subsequently used as a precursor for the production of La2Ti2O7 and Nd2Ti2O7. We suggest, based on the results of 13C NMR spectroscopy, that mixed-metal chelate complexes, (La,Ti)-CAn or (Nd,Ti)-CAn, formed in starting CA-EG solutions. The formation of pure La2Ti2O7 and Nd2Ti2O7 occurred when the precursor was heat treated in a furnace set at 700°C and 800°C respectively in static air for 4 h.
AB - A polymerized complex technique was utilized to prepare high-purity La2Ti2O7 and Nd2Ti2O7. Heating of mixed solutions of citric acid (CA), ethylene glycol (EG), La (or Nd) and Ti ions with a molar ratio of CA:EG:La(or Nd):Ti = 5:20:1:1 at 130°C produced a yellowish transparent polymeric gel without any precipitation, which was subsequently used as a precursor for the production of La2Ti2O7 and Nd2Ti2O7. We suggest, based on the results of 13C NMR spectroscopy, that mixed-metal chelate complexes, (La,Ti)-CAn or (Nd,Ti)-CAn, formed in starting CA-EG solutions. The formation of pure La2Ti2O7 and Nd2Ti2O7 occurred when the precursor was heat treated in a furnace set at 700°C and 800°C respectively in static air for 4 h.
KW - C NMR spectroscopy
KW - LnTiO
KW - Mixed-metal chelate
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U2 - 10.1016/0925-8388(96)02323-7
DO - 10.1016/0925-8388(96)02323-7
M3 - Article
AN - SCOPUS:0030231552
SN - 0925-8388
VL - 242
SP - 6
EP - 10
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
IS - 1-2
ER -