Premium
Thermodynamic Study of Reduced Phases in the BaLa 4 Cu 5 O 13.1− x System
Author(s) -
Thiele Erik,
Davies Peter K.
Publication year - 1991
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1991.tb04336.x
Subject(s) - perovskite (structure) , cuprate , enthalpy , chemistry , standard enthalpy of formation , analytical chemistry (journal) , differential scanning calorimetry , copper , metal , oxygen , doping , crystallography , thermodynamics , materials science , physics , optoelectronics , organic chemistry , chromatography
The thermodynamic stabilities of reduced, perovskiterelated cuprates with the BaLa 4 Cu 5 O 13.1− x structure were investigated using differential scanning calorimetry techniques. For 0 < x 0.6 the partial molar enthalpy of oxygen in the structure is constant at ‐187.4 kJ/mol O 2 . This value is almost identical to those reported for other perovskite cuprates. These results suggest that −190 kJ is a reliable value for the oxidation of Cu from 2 + to 3 + and can be used with confidence in calculations of the stabilities of the p ‐doped perovskite cuprates. Anomalously large enthalpies measured for samples prepared with higher values of x under forming gas probably result from trace contaminants of Cu metal.