Thermodynamics Research Center / ThermoML | Thermochimica Acta

Thermodynamic Measurement of Nd-Fe system by Double Knudsen Cell Mass Spectrometry

Nagai, T.[Takashi], Shirai, S.[Sho], Maeda, M.[Masafumi]
Thermochim. Acta 2011, 516, 1-2, 8-12
ABSTRACT
The activities of Nd in the Nd-Fe alloys were determined by double Knudsen cell mass spectrometry. The activities of Nd in Nd-Fe alloys with Nd concentration from 8.5 to 93 at% were determined at 1373 - 1523 K, measuring the ion current of vapor of Nd in equilibrium with Nd-Fe melts, Nd2Fe17 + pounds^Fe, Nd2Fe17 + liquid, and pounds^Fe + liquid. The standard Gibbs energy of formation of Nd2Fe17 was calculated from the activities of Nd obtained from the measurement, as follows: 2Nd ( ) 17Fe ( ) Nd Fe ( ) 2 17 l y * - s 238000 130 (21000) J/mol (1373-1473K) f Nd2Fe17 'G - { y T b ss The activities of Fe in Nd-Fe alloys were calculated based on the Gibbs-Duhem equation.
Compounds
# Formula Name
1 Nd neodymium
2 Fe iron
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
  • 2
  • 1
  • (Relative) activity - 1 ; Crystal
  • Temperature, K; Crystal
  • Mole fraction - 1; Crystal
  • Pressure, kPa; Crystal
  • Crystal
  • Mass-spectrometry
  • 11
  • POMD
  • 2
  • 1
  • (Relative) activity - 1 ; Liquid
  • Temperature, K; Liquid
  • Mole fraction - 1; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Mass-spectrometry
  • 12