Compounds in the system Cs-Te at room temperature

Thermodynamic assessment of the Cs–Te binary system

“…For samples in the range 0.8 ox(Te) o0.95, the solid/solid phase transition in CsTe 4 reported by Prins and Cordfunke [13] at 498 K could also possibly explain the thermal events detected by Chuntonov et al at 488 K. However, existence of this transition needs further experimental confirmation and has not been taken into account in the present optimization. …”

“…But, both studies agree on the 40 In 1984, Prins and Cordfunke [13] have investigated the Cs-Te system by X-ray powder diffraction experiments. They found that the compounds Cs 2 Te, Cs 3 Te 2 , Cs 2 Te 3 and Cs 2 Te 5 are stable at room temperature.…”

“…Their crystal structures were also identified. However, Prins and Cordfunke [13] employing a different synthesis method have found that CsTe 4 was in equilibrium with pure Te instead of such compounds. In the following, these polytellurides will not be taken into account due to the lack of data but it is possible that the phase equilibria in the composition range between CsTe 4 and pure Te are much more complex than indicated in the critical assessments of Sangster and Pelton and Okamoto.…”

“…An alternative method is based on the fact that, even if both elements have a significant vapor pressure above 900 K (P Cs and P Te reach 1 atm at respectively 944 K and 1261 K [15], Cs is much more volatile than Te. This characteristic has been used by Chuntonov et al [16], Cordfunke and coworkers [13,[17][18][19][20][21], Schewe-Miller and Böttcher [22] to synthesize Cs-Te samples by solid gas reaction. The principle of the method is to put solid quantities of Cs and Te in separate compartments of a common reaction volume.…”

“…-The reactivity between Cs and Te is very high. Prins and Cordfunke [13] mentioned that a violent reaction occurs when Cs and Te are directly mixed. Likewise, if Te powder is in contact with Cs in a sealed glass ampoule, slight heating above room temperature resulted in an explosive reaction cracking of Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/calphad the ampule.…”