The standard enthalpies of formation of Bi25FeO39 (s) and Bi2Fe4O9 (s), at 298.15 K were determined by acid solution calorimetry and are found to be ( 7.55 +- 0.32) 103 kJ mol 1 and ( 2.17 +- 0.07) 103 kJ mol 1, respectively. Heat capacities of Bi25FeO39 (s) and Bi2Fe4O9 (s) were measured using differential scanning calorimetry (DSC). The measured heat capacities as a function of temperature are expressed as: Cp less thanBi25FeO39greater than (JK 1 mol 1) +- 49.9 = 1529.9 + 200.6 10 3 T 21.6 106 T 2 (T/K: 308 818), Cp less thanBi2Fe4O9greater than (JK 1 mol 1) +- 11.0 = 395.5 23.0 10 3 T 7.6 106 T 2 (T/K: 313 773). Deviation of measured Cp values from the estimates by the Neumann-Kopp rule (NKR) has also been discussed.
Compounds
#
Formula
Name
1
Fe
iron
2
Bi
bismuth
3
O2
oxygen
4
Bi2Fe4O9
bismuth ferrite (Bi2Fe4O9)
5
Bi2O3
bismuth oxide
6
Fe2O3
ferric oxide
Datasets
The table above is generated from the ThermoML associated json file (link above).
POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied;
the numbers refer to the table of compounds on the left.
Type
Compound-#
Property
Variable
Constraint
Phase
Method
#Points
POMD
4
Molar heat capacity at constant pressure, J/K/mol ; Crystal
Temperature, K; Crystal
Pressure, kPa; Crystal
Crystal
Small sample (50 mg) DSC
11
POMD
5
Molar heat capacity at constant pressure, J/K/mol ; Crystal
Temperature, K; Crystal
Pressure, kPa; Crystal
Crystal
Small sample (50 mg) DSC
13
POMD
5
6
Molar heat capacity at constant pressure, J/K/mol ; Crystal of intercomponent compound 1
Temperature, K; Crystal of intercomponent compound 1
Pressure, kPa; Crystal of intercomponent compound 1
Amount ratio of solute to solvent - 5; Crystal of intercomponent compound 1