I. V. Tananaev Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials, Kola Scientific Centre, Russian Academy of Sciences

M. N. Palatnikov, Head of Laboratory, e-mail: palat_mn@chemy.kolasc.net.ru
O. B. Shcherbina, Researcher
N. V. Sidorov, Head of Department
V. T. Kalinnikov, Director of the Institute

In our experiments, lanthanide-doped (Gd, Er) lithium niobate crystals and nominally pure crystals of congruent and stoichiometric compositions were grown under non-steady-state thermal conditions. By comparing the Raman spectra in lithium niobate single crystals of dissimilar composition, we studied the fine peculiarities of their structural ordering. The growth regular domain microstructures and periodic nano-size structures with a spacing of 10 to 100 nm were examined using the optic and atom-absorption methods. It was noted that periodic clusters in lithium niobate structure may emerge in proximity of Nb_Li own defects forming ordered sublattices as large as several translation periods, i. e. with a 1–2 nm spacing. In such single crystals with periodic micro- and nanostructures, in the practically significant temperature range of 300–380 K, a series of anomalies of different electrophysical properties has been observed. The peculiarities of electrophysical characteristics of lithium niobate single crystals with micro- and nanostructures of the fractal type have been investigated.

1. Dmitriev V. G., Tarasov L. V. Prikladnaya nelineynaya optika (Applied non-linear optics). Moscow, 2004. 512 p.
2. Akhmanov S. A., Nikitin S. Yu. Fizicheskaya optika (Physical Optics). Moscow, 2004. 656 p.
3. Antipov V. V., Blistanov A. A., Sorokin N. G., Chizhikov S. I. Kristallografiya — Crystallographics. 1985. Part. 30,Vol. 4. pp. 734–738.
4. Ito H., Takyu C., Inaba H. Electron. Lett. 1991. Vol. 27, No. 14. pp. 1221–1226.
5. Magel G. A., Fejer M. M., Byer R. L. Appl. Phys. Lett. 1990. Vol. 56, No. 2. pp. 108–112.
6. Shur V. Ya., Rumyantsev E. L., Bachko R. G., Miller G. D., Feyer M. M., Bayer R. L. FTT — Physics of Solid Body. 1999. Part. 41, Vol. 10. pp. 1831–1837.
7. Naumova I. I. Kristallografiya — Crystallographics. 1994. Part. 39, No. 6. pp. 1119–1122 .
8. Naumova I. I., Gliko O. A. Kristallografiya — Crystallographics. 1996. Part. 41, No. 4. pp. 749–750.
9. Naumova I. I., Evlanova N. F., Gliko O. A., Lavrishchev S. V. J. Cryst. Growth. 1997. Vol. 181. pp. 160–164.

10. Bermudez V., Serrano M. D., Dieguez E. J. Cryst. Growth. 1999. Vol. 200, No. 1/2. pp. 185–190.
11. Palatnikov M., Shcherbina O., Biryukova I., Sidorov N. Ferroelectrics. 2008. Vol. 374. pp. 41–46.
12. Kulikova N. V., Khmelevskaya V. S., Bondarenko V. V. Mat. modelir. — Mathematical Simulation. 2006. Part. 18, No. 1, pp. 88–98.
13. Sidorov N. V., Palatnikov M. N., Serebryakov Yu. A., Lebedeva E. L., Kalinnikov V. T. Neorgan. Materialy — Inorganic Materials. 1997. Part. 33, No. 4. pp. 496–506.
14. Sidorov N. B., Palatnikov M. H., Kalinnikov V. T. Optika i spektroskopiya — Optics and Spectroscopy. 1997. Part 82, No. 1. pp. 38–44.
15. Sidorov N. V., Volk T. R., Mavrin B. N., Kalinnikov V. T. Niobat litiya : defekty, fotorefraktsiya, kolebatelnyy spektr, polyaritony (Litium niobates: defects, photorefraction, vibrational spectrum, polaritons). Moscow, 2003. 255 p.
16. Voskresenskiy V. M., Starodub O. R., Sidorov N. V., Palatnikov M. N., Mavrin B. N. Kristallografiya —Crystallographics. 2011. Part. 56, No. 1. pp. 26–32.