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MONOCRYSTALS YAG AND SrTiO AND THEIR SPECTRA – GAP MEASUREMENTS
3
RESEARCH RESULTS

FILIP RISTOSKI

Based on the energy gap of the sample SrTiO 3 , which is n
Jove Ilića 98, 11010 Belgrade
the wavelength of 403 nm and amounts to 3.08 eV, it

belongs to the group of semiconductors. The tested sample,

INTRODUCTION

Spectrophotometry is the quantitative measurement of the
reflection or transmission properties of a material as a
function of wavelength. It deals with visible light, near-
ultraviolet and near infrared. Spectrophotometry is to meet
the following requirements – maximum sensitivity is Picture 3 GAP measurements of YAG
realized by measurements, minor changes in wavelength do
not affect reproducibility (usually measured at a wavelength
of maximum absorption) and Beer-Lambert Law is applied. Table 1. Values of the samples provided by the research
YAG (Y 3 Al 5 O 12 ) Yttrium aluminium garnet is a synthetic Samples %T max (eV) (eV) Eg(eV)
crystal material belonging to the garnet group. (Picture 1). It SrTiO 3 54% 384nm 3.08
3.08
3.18
is used for grinding, cutting, laser production. It is applied in YAG 52% 259nm 4.45 3.18 4.12
the fields of medicine, dentistry and spectroscopy.

CONCLUSION

Permeability values of both samples is over 50 % in the
visible part of the spectrum. However, StTiO 3 possesses
higher maximum permeability. The color of monocrystal is
based on the absorption maximum. The absorption
Picture 1 YAG Picture 2 SrTiO 3 maximum matches the color of the analyzed samples. The
minimum energy of direct transport is 3.18 eV at SrTiO 3 and
Strontium titanate (SrTiO 3 ) is an oxide of strontium and minimum energy of indirect transport is 3.08 eV. As for
titanium (Picture 2). The most significant application of its YAG, the minimum energy of direct transport is 4.45 eV
synthetic form is in optical instruments and ceramics. and minimum energy of indirect transport is 3.18 eV (Table
1.).
WORKING METHOD
LITERATURE
This research analyzed the samples of monocrystal Yag
(2,07 mm thick) and SrTiO 3 (2,19 mm thick). [1] Hamdan K., Mohamad K. I Zuhairi I. “Optical
Properties Of Ti:Al2O3 Single Crystal”, J. Fiz UTM.
The measurements were carried out by performing UV‒Vis Vol.4. 42-49 pp. 2009.
method, and it was recorded on UV-VIS-NIR
Spectrophotometer. Spectrophotometry measurements were [2] Ana B.,Eduardo A.,Luis S.,"First-Principles Study of the
carried out in the laboratory at room temperature. The Strucutre and the Electronic Structure of Yttrium Aluminium
recording was performed in the interval of 180 -800 nm and Garnet Y3Al5O12",2009.,International Journal of Quantum
10 nm steps. Chemist, Vol 109, 2009.
The objective of this research is to determine optical [3] Yanfeng G., Yoshitake M., and Kunihito K.” Band Gap
properties of the selected monocrystals based on Energy of SrTiO3 Thin Film Prepared by the
measurements and define the group of materials they belong Liquid Phase Deposition Method” , Journal of the Korean
to, based on energy gaps. Ceramic Society, Vol. 40, No. 3, pp. 213-218, 2003.