@article{
author = "Golubović, Aleksandar and Gajić, Radoš and Nikolić, Slobodanka and Djurić, Stevan and Valčić, Andreja",
year = "2000",
abstract = "LiNbO3 single crystals were grown by the Czochralski technique in an air
atmosphere. The critical crystal diameter Dc = 1.5 cm and the critical rate of rotation wc
= 35 rpm were calculated from the dynamic of fluids equations for buoyancy-driven
and forced convections under which the shape of the melt/crystal interface changed. The
domain inversion was carried out at 1473 K using a 10 min 3.75 V/cm electric field.
The obtained crystals were cut, polished and etched to determine the presence of
dislocations and single domain structures. The lattice parameters a = 0.51494 nm, c =
1.38620 nm and V = 0.3186 nm
3
were determined by X-ray powder diffraction. The
optical properties were studied by infrared spectroscopy in the wave number range 20
5000 cm
-1
. With decreasing temperature, an atypical behaviour of the phonon modes,
due to the ferroelectric properties of LiNbO3 single crystal, could be seen. The optical
constants were calculated by Kramers-Kronig analysis and the value of the critical
temperature was estimated. The obtained results are discussed and compared with
published data., Monokristali LiNbO3 su dobijeni metodom rasta kristala po Čohralskom na
vazduhu.Iz jednačina dinamike fluida za termičku i forsiranu konvekciju izračunati
su kritični prečnik kristala Dc
= 1,5 cm i vrednost kritične brzine rotacije wc = 35
o/min pri kojima dolazi do promene oblika fronta kristalizacije. Monodomenizacija
je obavljena na temperaturi od 1473 K, pri električnom polju od 3,75 V/cm u trajanju od
10 minuta. Dobijeni kristali su sečeni, polirani i nagrizani da bi se odredilo
prisustvo dislokacija i dobijanje monodomenske strukture. Rendgenskom difrakcijom
praha odredjeni su parametri jedinične ćelije a = 0,51494 nm
, c = 1,38620 nm i zapremina
V = 0,3186 nm
3
.Optičke osobine su proučavane u infracrvenoj oblasti spektra u opsegu
talasnih brojeva od 20–5000 cm
–1
. Refleksioni spektri su snimani na različitim
temperaturama da bi se posmatrao položaj fononskih modova. Sa opadanjem temperature
može da se vidi atipično ponašanje fononskih modova što se pripisuje feroelektričnim
osobinama monokristala LiNbO3. Optičke konstante monokristala LiNbO3 su
dobijene korišćenjem Kramers-Kronig analize i procenjena je vrednost kritične temperature.Dobijeni rezultati su diskutovani i uporedjivani sa podacima iz literature.",
publisher = "Belgrade : Serbian Chemical Society",
journal = "Journal of the Serbian Chemical Society",
title = "The crystallization and optical properties of LiNbO3 single crystals, Kristalizacija i optičke osobine monokristala LiNbO3",
volume = "65",
number = "5-6",
pages = "391-397",
doi = "10.2298/JSC0006391G"
}
