On Isotropic Points in Potassium Ammonium Sulphate Crystals
- Авторы: Stadnyk V.1, Shchepanskyi P.1,2, Brezvin R.1, Rudysh M.1,2, Kohut Z.3, Onufriv O.4, Kost Y.5
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Учреждения:
- Ivan Franko Lviv National University
- Jan Dlugosz University in Czestochowa, 42-200
- Lviv Polytechnic National University
- Ukranian National Forestry University
- Karpenko Physico–Mechanical Institute of the National Academy of Sciences of Ukraine
- Выпуск: Том 64, № 5 (2019)
- Страницы: 787-792
- Раздел: Physical Properties of Crystals
- URL: https://journals.rcsi.science/1063-7745/article/view/194223
- DOI: https://doi.org/10.1134/S1063774519050201
- ID: 194223
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Аннотация
An effect of uniaxial pressure on the spectral and temperature dependences of birefringence of K1.75[NH4]0.25SO4 single crystals has been studied. Different changes in the birefringence are found for different compression directions. The possibility of the occurrence of isotropic points in the crystal under uniaxial compression is discussed. A decrease in the birefringence under crystal heating is established, and the positions of two isotropic points in the range of 290–630 K are determined. The partial isomorphic substitution of NH4 ions for K ions was found to result in a shift of isotropic points to lower temperatures.
Об авторах
V. Stadnyk
Ivan Franko Lviv National University
Автор, ответственный за переписку.
Email: vasylstadnyk@ukr.net
Украина, Lviv, 79005
P. Shchepanskyi
Ivan Franko Lviv National University; Jan Dlugosz University in Czestochowa, 42-200
Автор, ответственный за переписку.
Email: pavloshchepanskyi@gmail.com
Украина, Lviv, 79005; Czestochowa
R. Brezvin
Ivan Franko Lviv National University
Email: pavloshchepanskyi@gmail.com
Украина, Lviv, 79005
M. Rudysh
Ivan Franko Lviv National University; Jan Dlugosz University in Czestochowa, 42-200
Email: pavloshchepanskyi@gmail.com
Украина, Lviv, 79005; Czestochowa
Z. Kohut
Lviv Polytechnic National University
Email: pavloshchepanskyi@gmail.com
Украина, Lviv, 79013
O. Onufriv
Ukranian National Forestry University
Email: pavloshchepanskyi@gmail.com
Украина, Lviv, 79057
Ya. Kost
Karpenko Physico–Mechanical Institute of the National Academy of Sciences of Ukraine
Email: pavloshchepanskyi@gmail.com
Украина, Lviv, 79060