Molar heat capacities of the tellurites MnTeO3, MnTe2O5, and Mn2Te3O8

Vaporization Thermodynamic Studies by High-Temperature Mass Spectrometry on Some Three-Phase Regions over the MnO−TeO2 Binary Line in the Mn−Te−O Ternary System

“…To our knowledge, the only thermodynamic data available in the literature are the heat capacities for the phases MnTeO 3 , Mn 2 Te 3 O 8 , and MnTe 2 O 5 reported by Gospodinov and Mihov. 3 Our interest in vaporization thermodynamic studies of the Mn-Te-O system was basically motivated by our belief that, for a better understanding of fission-product tellurium-assisted clad corrosion in mixed-oxidefuelled fast breeder nuclear reactors, one needs to consider the formation of ternary oxide phases involving tellurium and stainless steel (SS) clad components in addition to that of binary tellurides. Especially so, if the O/M (M ) U + Pu) of the fuel outer-surface were to ever become hyper-stoichiometric, that is, greater than 2.…”

“…We have conducted systematic vaporization studies over the four three-phase regions Mn 3 O 4 + MnO + Mn 6 Te 5 O 16 ; Mn 3 O 4 + Mn 6 Te 5 O 16 + MnTeO 3 ; Mn 3 O 4 + Mn 3 TeO 6 + MnTeO 3 ; and Mn 3 TeO 6 + MnTeO 3 + Mn 2 Te 3 O 8 in the temperature range 850−950 K. The main objectives were to obtain p − T relations for the gaseous species TeO 2 (g), TeO(g), and Te 2 (g) in the equilibrium vapor over these phase fields, deduce thermodynamic data for various heterogeneous reactions in each phase field as well as for the homogeneous gas-phase reaction TeO 2 (g) + 0.5Te 2 (g) = 2TeO(g), and finally deduce the thermodynamic data for the ternary phases Mn 6 Te 5 O 16 , MnTeO 3 , Mn 3 TeO 6 , and Mn 2 Te 3 O 8 . To our knowledge, the only thermodynamic data available in the literature are the heat capacities for the phases MnTeO 3 , Mn 2 Te 3 O 8 , and MnTe 2 O 5 reported by Gospodinov and Mihov . Our interest in vaporization thermodynamic studies of the Mn−Te−O system was basically motivated by our belief that, for a better understanding of fission-product tellurium-assisted clad corrosion in mixed-oxide-fuelled fast breeder nuclear reactors, one needs to consider the formation of ternary oxide phases involving tellurium and stainless steel (SS) clad components in addition to that of binary tellurides.…”

Identification, Characterization and Properties of Apatites

“…based on the approach of ALDABERGENOV et al [185] and GOSPODINOV and MIHOV [186]. The molar heat capacity in homological series as A m (B x O y ) n , is a linear function of n, i.e.…”

Univariant Three- and Four-Phase Vaporization Equilibria in the Ternary Mn−Te−O System: A High-Temperature Mass Spectrometric Study of Binary xMnO + (1 − x)TeO2 with x ≥ 0.5

“…The ternary compounds known − in the Mn−Te−O system are as follows: Mn 6 Te 5 O 16 , MnTeO 3 , Mn 2 Te 3 O 8 , MnTe 2 O 5 , and MnTe 6 O 13 (phases along the MnO−TeO 2 binary line); Mn 3 TeO 6 (a 3:1 phase along the MnO−TeO 3 line or a 1:1 phase along the Mn 3 O 4 −TeO 2 line); Mn 2 TeO 6 (a 2:1 phase along the MnO 2 −TeO 2 binary line). While the phase diagram 17 for the MnO−TeO 2 binary system with x (MnO) = 0−0.5 and heat capacities 18 for MnTeO 3 , Mn 2 Te 3 O 8 , and MnTe 2 O 5 are reported in the literature, no vaporization study exist nor does a composition diagram depicting the existence of different three-phase regions.…”

“…The ternary compounds known [14][15][16][17][18] in the Mn-Te-O system are as follows: Mn 6 Te 5 O 16 , MnTeO 3 , Mn 2 Te 3 O 8 , MnTe 2 O 5 , and MnTe 6 O 13 (phases along the MnO-TeO 2 binary line); Mn 3 -TeO 6 (a 3:1 phase along the MnO-TeO 3 line or a 1:1 phase along the Mn 3 O 4 -TeO 2 line); Mn 2 TeO 6 (a 2:1 phase along the MnO 2 -TeO 2 binary line). While the phase diagram 17 for the MnO-TeO 2 binary system with x(MnO) ) 0-0.5 and heat capacities 18 for MnTeO 3 , Mn 2 Te 3 O 8 , and MnTe 2 O 5 are reported in the literature, no vaporization study exist nor does a composition diagram depicting the existence of different three-phase regions. There is also some doubt as to whether Mn 6 -Te 5 O 16 (formerly designated as Mn 4 Te 3 O 10 ) is really a stable phase 14 and thus qualified to be the most MnO-rich phase in the MnO-TeO 2 binary system in view of its tendency to decompose to MnTeO 3 and Mn 3 TeO 6 on being heated for long duration at T ) 923 K. Our investigations in the Mn-Te-O system had the objectives of filling these gaps.…”