Optical and Dilatometric Manifestations of Phase Transitions in K2SeO4 Crystal |
| B. Andriyevsky and O. Myshchyshyn L'viv State University, 8 Kyryla and Mefodiya Sir., 290005, L'viv, Ukraine |
| Received: April 23, 1997 |
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| Temperature dependencies of the characteristic optical paths difference D(Τ) of K2SeO4 crystal in the range of 80-295 K were measured using the Jamen type interferometer. Significant anomalies of D(Τ) dependencies in the vicinity of incommensurate-paraelectric phase transition (Ti = 130 K) are observed. On the basis of D(Τ) temperature dependencies measured experimentally and linear expansion l(Τ) known, the temperature derivative of the refractive indices dn/dT are found to be negative in the ranges above and below the temperature Ti=130 K. |
| DOI: 10.12693/APhysPolA.92.557 PACS numbers: 64.70.Kb, 78.20.Fm |