- Tytuł:
- Optical Investigations of Phase Transitions in (NH$\text{}_{4}$)$\text{}_{2}$SbF$\text{}_{5}$ Crystal
- Autorzy:
-
Andriyevsky, B.
Czapla, Z.
Stadnyk, V. - Powiązania:
- https://bibliotekanauki.pl/articles/1932114.pdf
- Data publikacji:
- 1995-03
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Tematy:
-
64.70.Kb
78.20.Fm - Opis:
- Results of optical thickness and refractive indices measurements for (NH$\text{}_{4}$)$\text{}_{2}$SbF$\text{}_{5}$ crystal in the temperature range 100-310 K are presented. The measurements were done with interference method using He-Ne laser (λ = 632.8 nm). At T$\text{}_{c1}$ = 292 K and T$\text{}_{C2}$ = 168 K two continuous phase transitions with critical indices β$\text{}_{1}$ = 0.38 and β$\text{}_{2}$ ≤ 0.57 were observed. Additional anomaly of temperature changes of interference order with maximum at T$\text{}_{c3}$ ≈ 132 K were found. This anomaly resembles a diffused transition. Temperature-averaged values of derivatives of refractive indices dn$\text{}_{g}$ /dT = -3.3 × 10$\text{}^{-5}$ K and dn$\text{}_{m}$/dT = -2.9 × 10$\text{}^{-5}$ K$\text{}^{-1}$ evidenced a decrease in optical anisotropy (birefringence) along the b-axis on heating run.
- Źródło:
-
Acta Physica Polonica A; 1995, 87, 3; 611-617
0587-4246
1898-794X - Pojawia się w:
- Acta Physica Polonica A
- Dostawca treści:
- Biblioteka Nauki