| Abstract: | Based on the data from optical-spectral studies of (NH2(CH3)2)2CoCl4 crystals, the existence of high-temperature phase transitions at 419, 380, 352, and 313 K is confirmed. It was shown that with the exception of the first transition, they are related to a considerable extent to rearrangement of the network of hydrogen bonds and are not accompanied by, considerable deformation of the lattice. In this connection the character of the electron-phonon interaction remains unchanged in the entire temperature range of the measurements. The (NH2(CH3)2)2CoCl4 structure at room temperature is close to that of the ordered low-temperature phases of such isomorphous crystals as β-K2SO4. I. Franko State University, L’vov, Ukraine, 8, Kirill and Mefodii St., UA-290005, L’vov. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 3, pp. 412–418, May–June, 1998. |
