Nanocomposites and nanomaterials 

Raman scattering in nanomaterials based on synthetic opals and active dielectrics K2ZnCl4 and LiIO3 
Moiseyenko V.N., Shlega S., Oleinik B. 
Physics, Electronics and Computer Systems Department, Oles Honchar Dnipro National University. Prospect Gagarina, 72, Dnipro-49010, Ukraine. 
E-mail: vnmois@ukr.net 

The work is devoted to the creation and study of Raman spectra of new nanomaterials based on synthetic opals and crystals of ferroelectric with an incommensurate phase K2ZnCl4 (403 - 553 К) [1] and nonlinear optical crystals α-LiIO3 [2]. K2ZnCl4 and α-LiIO3 are convenient objects and can be introduced into the pores of opal both from aqueous saturated solution and from melt at relatively low temperatures.
Filling of the pores of opals was carried out by the method of repeated dipping the opals into a saturated aqueous solution of K2ZnCl4 or LiIO3 at a temperature of 60oC. After each dipping, the sample was dried in air, then in a resistance furnace at 120°C, and again dipping in the solution. 
For all samples of nanomaterials, the maximum of the Bragg reflection band was shifted to the long-wavelength region of the spectrum due to an increase in the effective permittivity. The Raman spectra were recorded in reflection geometry using a modified DFS-12 double-monochromator laser spectrometer. The spectra were excited by continuous laser radiation with wavelengths of 532 nm. 
In all cases, the measured Raman spectra corresponded to the crystalline phase state of the injected substance in the pores of the opal matrix. Comparison of the measured Raman spectra of nanomaterials with the spectra of single crystals showed the absence of new bands in opal - K2ZnCl4 and opal - LiIO3 nanocomposites, but the parameters of the spectral components changed. 

1.	Gorelik V.S., Moiseenko V.N., Pastukhov V.I. Scattering of light in a 	ferroelectric with incommensurate phase: K2ZnCl4 // J. of Russian Laser 	Research.-1995.-16, Issue 1.-P. 57–82. 
2.	 Teyssier J., Le Dantec R., Galez C., Mugnier Y., Bouillot J. and Plenet 	J.-C. LiIO3 nanocrystals in SiO2 xerogels, a new material for non-linear optics 	// SPIE's 48th Annual Meeting, 2003, San Diego, California, United States. 	Proceedings of SPIE, Nanocrystals and Organic Hybrid 	Nanomaterials.-2003.-5222 (26).