Abstract
A portion of the constitutional diagram of the LaNb3O9 – NaNbO3 system in the temperature range from 20 to 800°C is constructed. The existence of a solid-solution region (down to 10 mol.% NaNbO3 ) involving a low-temperature monoclinic modification of LaNb3O9 and of a broad region (from 20 to 75 mol.% NaNbO3 ) of tetragonal perovskite solid solutions is established. High-temperature perovskite solid solutions based on the LaNb3O9 rhombic modification undergo an eutectoid decomposition into two perovskite solid solutions. LaNb3O9 and the high-temperature solid solutions are shown to be antiferroelectric phases with high values of dielectric constant.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
REFERENCES
S. P. Solov'ev, Yu. N. Venevtsev, and G. S. Zhdanov, “An x-ray diffractometric study of phase transitions in NaNbO3,” Kristallografiya, 6(2), 217-224 (1961).
A. M. Sych, V. P. Dem'yanenko, L. A. Zastavker, and M. M. Nekrasov, “IR spectra and electrophysical properties of lanthanum metaniobate, ” Izv. Akad. Nauk SSSR, Neorg. Mater.,9(11), 1947-1950 (1973).
A. P. Pivovarova, V. I. Strakhov, and O. V. Mel'nikova, “High-Temperature effects in the NaNbO3–LaNb3O9 system,” Neorg. Mater., 35(9), 1-2 (1999).
Y. Sturm and R. Azuehn, “Eine neue LaNb3O9 modification,” Naturwissenschaften, 62(6), 296-297 (1975).
Rights and permissions
About this article
Cite this article
Pivovarova, A.P., Strakhov, V.I. & Popov, V.P. Phase Relations in the LaNb3O9 – NaNbO3 System in the Temperature Range of 20 TO 800°C. Refractories and Industrial Ceramics 42, 285–287 (2001). https://doi.org/10.1023/A:1012718529213
Issue Date:
DOI: https://doi.org/10.1023/A:1012718529213