Journal of Physical Studies 10(4), 358–380 (2006) DOI: https://doi.org/10.30970/jps.10.358 SPECTRAL REFRACTOMETRY OF THE FERROICS OF TRIGLYCINE SULFATE GROUP, ROCHELLE SALT AND POTASSIUM SULFATE CRYSTALS M. O. Romanyuk Ivan Franko National University of Lviv, Department for Experimental Physics 8, Kyryla i Mefodija St., Lviv, UA–79005, Ukraine

The methods for measuring of refractive indices, optical anisotropy, temperature (4.2-1000 K) and spectral (230-800 nm) dependencies of the electronic polarization of the dielectric ferroics are described. The optical birefringence sign-inversion ($Δ n = 0$), radiation-induced refraction indices changing sign inversion, anomalies of piezooptic coefficients at phase transitions are detected. The parameters of effective oscillators are computed. The crystal optic method for creating the temperature reference points, for measuring temperature and doses of hard radiation is presented.

It is determined that the refraction indices and birefringence of ferroics of the groups of Rochelle salt, triglycinesulfate and potassium sulfate are in the range $1.4 The spectral dependence $n(λ)$ is satisfactorily ($\pm 2 \cdot 10^{-4}$) described by binomial dispersion expression which includes UV and IR oscillators. All oscillator parameters depends on temperature. Their real absorption bands are in the range 9-15 eV and has 2-3 maximums, between which there are the maximums of the effective oscillators.

There are presented parameters of dispersion expression and reference values of refractive indices for 25 crystals and parameters of optical birefringence sign inversion for 15 crystals.

PACS number(s): 78.20.Hp, 77.80.Bh, 77.84.Fa, 78.20.Ci

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