Structural Features of PLZT Films
| Autor: | G. B. Kuznetsov, O. M. Zhigalina, K. A. Vorotilov, V. Yu. Kolosov, D. N. Khmelenin, A. S. Sigov, Yu. A. Valieva, A. O. Bokuniaeva |
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| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Materials science Annealing (metallurgy) Doping Analytical chemistry Pyrochlore chemistry.chemical_element Crystal growth 02 engineering and technology General Chemistry Chemical vapor deposition engineering.material 021001 nanoscience & nanotechnology Condensed Matter Physics Lead zirconate titanate 01 natural sciences chemistry.chemical_compound Tetragonal crystal system chemistry 0103 physical sciences engineering Lanthanum General Materials Science 0210 nano-technology |
| Zdroj: | Crystallography Reports. 63:646-655 |
| ISSN: | 1562-689X 1063-7745 |
| DOI: | 10.1134/s1063774518040314 |
| Popis: | Lead zirconate titanate (PZT) films doped with lanthanum, Pb(1–х)Laх(Zr0.48Ti0.52) (х = 0, 0.02, 0.05, 0.08, or 0.01), have been investigated by electron microscopy and X-ray diffraction. Films were formed on Si–SiO2–TiO2–Pt substrates by chemical vapor deposition from a solution and annealed at temperatures T = 650 and 750°C. The main structural features of the films, differing them from undoped PZT films fabricated by the same method, have been established. It is found that doping with lanthanum delays the pyrochlore–perovskite transformation in the film bulk, i.e., in the regions distant from the film–substrate interface. The fraction of metastable pyrochlore phase increases with an increase in the La molar content in the films. The main reason for the delay is the deficit of lead in the intergranular perovskite space, especially in the upper part of the film. Annealing at T = 750°C reduces the content of pyrochlore phase but does not completely remove it, which was never observed for undoped PZT films. Doping with lanthanum leads to a change in the lattice period c and a tetragonal distortion of the perovskite lattice (c/a ratio). Hence, the [100] texture of the films obtained, in contrast to the typical [111] texture of PZT films, is due to the increase in the lattice mismatch between the film and platinum layer when lead atoms are replaced with lanthanum. Lattice distortions of “transrotational” character, whose value exceeds 160 deg/μm, are found to arise in growing crystals. |
| Databáze: | OpenAIRE |
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