Abstract
Structural and elastic properties of chalcopyrite-type CuInSe2 are determined in almost full stability range of temperature from 11 to 1,073 K, by in situ X-ray diffraction, employing a synchrotron-radiation source. The studied polycrystalline sample was prepared from a stoichiometric single crystal. Phase analysis reveals the formation of a trace amount of indium oxide impurity phase at the highest temperatures studied. From the obtained smooth lattice-parameter dependencies on temperature, the temperature dependencies of thermal expansion coefficients are derived. These coefficients are found to follow the trends previously reported for narrow temperature intervals. The present results provide a clear experimental evidence that the linear expansion coefficient is slightly negative below 47 K in both, a and c, directions; this temperature limit is in between the previously reported theoretical value (35 K) and the experimental ones (60 and 80 K) of such limit.
Highlights
Copper indium diselenide, CuInSe2 (CIS), is one of the ternary compounds occurring in the CuSe2–In2Se3 phase diagram [1, 2]
The present results provide a clear experimental evidence that the linear expansion coefficient is slightly negative below 47 K in both, a and c, directions; this temperature limit is in between the previously reported theoretical value (35 K) and the experimental ones (60 and 80 K) of such limit
In [33], an average linear thermal expansion dependence on temperature has been calculated; the results show that the TEC becomes negative below about 35 K; the absolute TEC values are found to be much larger as compared to all experiments
Summary
CuInSe2 (CIS), is one of the ternary compounds occurring in the CuSe2–In2Se3 phase diagram [1, 2]. (In considerations of CIS and other chalcopyrite-type compounds, the tetragonal distortion defined as 1 - g is frequently used.) When surveying the structural data for CuInSe2, we noticed a considerable scatter of the reported a and c values. Studies on the thermal behavior of the lattice parameters of CuInSe2, usually based on X-ray diffraction, have covered limited temperature ranges: 301–839 K [26], 30–300 K [27]), 85–650 K [28] and 295–723 K [29] with typically a low number of experimental points; the most recent study [23] has been focused on the vicinity of the high-temperature tetragonal–cubic phase transition. The unit cell dimensions and TEC for CuInSe2 are determined in the 11–1,073 K temperature range; the obtained results are discussed on the ground of earlier reported data
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
