A Multistep Topotactic Route to the New Mixed-Valence Titanate, Na2-x+yCax/2La2Ti3O10. Electron Localization Effects in a Triple-Layered Perovskite

Inorganic Chemistry

Volumn 37, Issue 18, 1998, Pages 4484-4485

  Lalena, John N ^a   Cushing, Brian L ^a   Falster, Alexander U ^a   Simmons Jr , William B ^a   Seip, Candace T ^a   Carpenter, Everett E ^a   O'Connor, Charles J ^a   Wiley, John B ^a  

^a UNIVERSITY OF NEW ORLEANS   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0000181894     PISSN: 00201669     EISSN: None     Source Type: Journal    
DOI: 10.1021/ic980611g     Document Type: Article

References (28)

1. See, for example: (a) Sunstrom, J. E., IV; Kauzlarich, S. M.; Klavins, P. Chem. Mater. 1992, 4, 346. (b) Hamada, D.; Machida, M.; Sugahara, Y.; Kuroda, K. J. Mater. Chem. 1996, 6, 69. (c) MacEachern, M. J.; Dabkowska, J. D.; Garrett, J. D.; Amow, G.; Gong, W.; Liu, G.; Greedan, J. E. Chem. Mater. 1994, 6, 2092. (d) Edwards, P. P.; Ramakrishnan, T. V.; Rao, C. N. R. J. Phys. Chem. 1995, 99, 5228.
2. See, for example: (a) Sunstrom, J. E., IV; Kauzlarich, S. M.; Klavins, P. Chem. Mater. 1992, 4, 346. (b) Hamada, D.; Machida, M.; Sugahara, Y.; Kuroda, K. J. Mater. Chem. 1996, 6, 69. (c) MacEachern, M. J.; Dabkowska, J. D.; Garrett, J. D.; Amow, G.; Gong, W.; Liu, G.; Greedan, J. E. Chem. Mater. 1994, 6, 2092. (d) Edwards, P. P.; Ramakrishnan, T. V.; Rao, C. N. R. J. Phys. Chem. 1995, 99, 5228.
3. See, for example: (a) Sunstrom, J. E., IV; Kauzlarich, S. M.; Klavins, P. Chem. Mater. 1992, 4, 346. (b) Hamada, D.; Machida, M.; Sugahara, Y.; Kuroda, K. J. Mater. Chem. 1996, 6, 69. (c) MacEachern, M. J.; Dabkowska, J. D.; Garrett, J. D.; Amow, G.; Gong, W.; Liu, G.; Greedan, J. E. Chem. Mater. 1994, 6, 2092. (d) Edwards, P. P.; Ramakrishnan, T. V.; Rao, C. N. R. J. Phys. Chem. 1995, 99, 5228.
4. See, for example: (a) Sunstrom, J. E., IV; Kauzlarich, S. M.; Klavins, P. Chem. Mater. 1992, 4, 346. (b) Hamada, D.; Machida, M.; Sugahara, Y.; Kuroda, K. J. Mater. Chem. 1996, 6, 69. (c) MacEachern, M. J.; Dabkowska, J. D.; Garrett, J. D.; Amow, G.; Gong, W.; Liu, G.; Greedan, J. E. Chem. Mater. 1994, 6, 2092. (d) Edwards, P. P.; Ramakrishnan, T. V.; Rao, C. N. R. J. Phys. Chem. 1995, 99, 5228.
5. Examples here include: (a) Poeppelmeier, K. R.; Leonowicz, M. E.; Longo, J. M. J. Solid State Chem. 1982, 44, 89. (b) Nadiri, A.; Le Flem, G.; Delmas, C. J. Soild State Chem. 1988, 73, 338. (c) Armstrong, A. R.; Anderson, P. A. Inorg. Chem. 1994, 33, 4366.
6. Examples here include: (a) Poeppelmeier, K. R.; Leonowicz, M. E.; Longo, J. M. J. Solid State Chem. 1982, 44, 89. (b) Nadiri, A.; Le Flem, G.; Delmas, C. J. Soild State Chem. 1988, 73, 338. (c) Armstrong, A. R.; Anderson, P. A. Inorg. Chem. 1994, 33, 4366.
7. Examples here include: (a) Poeppelmeier, K. R.; Leonowicz, M. E.; Longo, J. M. J. Solid State Chem. 1982, 44, 89. (b) Nadiri, A.; Le Flem, G.; Delmas, C. J. Soild State Chem. 1988, 73, 338. (c) Armstrong, A. R.; Anderson, P. A. Inorg. Chem. 1994, 33, 4366.
8. McIntyre, R. A.; Falster, A. U.; Li, S.; Simmons, W. B.; O'Connor, C. J.; Wiley, J. B. J. Am. Chem. Soc. 1998, 120, 217.
9. Ionic radii from Shannon, R. D. Acta Crystallogr. 1976, A32, 751.
10. Mahler, C. H.; Cushing, B. L.; Lalena, J. N.; Wiley, J. B. Mater. Res. Bull. 1998, 33, in press. Cushing, B. L.; Wiley, J. B. Mater. Res. Bull. 1999, 34, in press.
11. Mahler, C. H.; Cushing, B. L.; Lalena, J. N.; Wiley, J. B. Mater. Res. Bull. 1998, 33, in press. Cushing, B. L.; Wiley, J. B. Mater. Res. Bull. 1999, 34, in press.
12. Wright, A. J.; Greaves, C. J. Mater. Chem. 1996, 6, 1823.
13. Toda. K.; Kameo, Y.; Fujimoto, M.; Sato. M. J. Ceram. Soc. Jpn. 1994, 102, 735.
14. Gopalakrishnan, J.; Bhat, V. Inorg. Chem. 1987, 26, 4299.
15. 10 does not form a hydrate and was stored in air.
16. 2 produced a poorly crystalline material with a limited degree of exchange.
17. Reductive intercalation was performed by heating the divalent exchange product with an equal mass of sodium metal (Alfa, 99.95%) in an evacuated Pyrex tube at 320 °C for 3 days. Excess sodium metal was removed by placing the tube in a temperature gradient (25 → 320 °C). The dark gray product showed slight air sensitivity so all samples were stored in an argon-filled drybox and any air exposure minimized. Caution: Sodium metal can react explosively with water. Excess sodium should be safely disposed of by reacting it with an alcohol.
18. Ratios of exchange cations were determined by electron microprobe, direct current plasma (DCP), and/or inductively coupled plasma (ICP) spectroscopy. The cation ratios (Na, Ca, La, and Ti) of the final product were determined commercially by ICP. The low value for lanthanum (1.93 versus 2.00) is attributed to the error in the ICP measurements, which can be several percent due to matrix effects; an error of less than 2% in both titanium and lanthanum would account for this difference. Samples for DCP and ICP were digested in a 10% HCl solution.
19. X-ray diffraction data were collected in step-scanning mode between 10 and 95° 2 θ with a 0.02° step width and 10 s count time on a Philips X'pert-MPD system (Cu Kα radiation, λ = 1.5418 Å) equipped with a graphite monochromator. Cell parameters were refined by a least-squares method. Magnetic susceptibility measurements were made on a Quantum Design MPMS-5S SQUID susceptometer between 2 and 300 K at 50 G (zero-field cooled) on polycrystalline samples before and after reductive intercalation. DC conductivity measurements of the reduced phase were taken between 2 and 300 K by the four-point probe method on a small rectangular unsintered pressed pellet; platinum leads were connected with silver paste.
20. 10 (ref 6) with the FORTRAN program LAZY-PULVERIX; Yvon, K.; Jeitschko, W.; Parthe, E. Laboratoire de Crystallographie aux Rayon-X, University Geneve: Geneva, Switzerland, 1977.
21. (a) Jones, R.; McKinnon, W. R. Solid State Ionics 1991, 45, 173.
22. (b) Sato, M.; Jin, T.; Ueda, H. Chem. Lett. 1994, 161.
23. 3 K/mol, respectively. The correlation coefficient (r) was 0.998. The compound is diamagnetic before reductive intercalation.
24. Mott, N. F. Conduction in Non-Crystalline Materials, 2nd ed.; Clarendon Press: Oxford, U.K., 1993 and the references therein.
25. -1/4) were fit to a linear function with a correlation coefficient of 0.993.
26. Yamaguchi, E.; Aoki, H.; Kamimura, H. J. Phys. C 1979, 12, 4801.
27. Kim, I.-S.; Itoh, M.; Nakamura, T. J. Solid State Chem. 1992, 101, 77.
28. Rousseau, R.; Palacin, M. R.; Gomez-Romero, P.; Canadell, E. Inorg. Chem. 1996, 35, 1179.