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In recent years growing interest has been expressed in obtaining information on the lattice dynamics of solids on the basis of experimental data on the heat capacity at low temperatures. This is accounted for by the fact that a comparison between experimental and theoretical results of phonon spectrum investigations allows one to choose or refine the parameters of a given theoretical model.The present report deals with an investigation of the heat capacity of TlGaTe2 in the temperature range from 5 to 300 K. Some phonon spectrum characteristics have been calculated, namely the n-th moments , w = (1/3N) J"." G(v)dv , 0 ; the Debye temperature at T-oo, @g),the temperature related to the entropy at T+-, v the geometric mean frequency, and EZ the zero vibrational energy of TlGaTe2 atoms in a harmonic approximation,The TlGaTe2 compound crystallizes in a TlSe-type complex chain structure /l/, TlGaTe2 specimens were obtained by fusing the initial components in evacuated and sealed quartz ampoules. A vacuum adiabatic unit with an automatic temperature control was used to measure C (T) /2/. The heat-capacity measurement e r r o r s amounted to 3 to 5% below 10 K, and 0.2 to 0.3% in the range from 10 to 300 K.The results of experimental heat-capacity measurements are depicted in Fig. 1. Inasmuch as the heat capacity of TlGaTe2 was measured for the first time, it was studied over the entire temperature range without any omissions. The heat-capacity behaviour failed to exhibit any anomalies due to phase transitions. 0 9 P Fig. 1 also gives the temperature dependence oi the Debye temperature QD calculated on the basis of levelled-off heat-capacity values. Below s s 8 K the 1) prospekt Narimanova 33, 370143 Baku, USSR.

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