Ab initio formation energies of Fe-Cr alloys
2003 (English)In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 321, no 1, 84-90 p.Article in journal (Refereed) Published
We have calculated ab initio lattice parameters, formation energies, bulk moduli and magnetic moments of Fe-Cr alloys. The results agree well with available experimental data. In addition to body centered cubic (bcc) alloys, which are representative of ferritic steels used in fast neutron reactors, face centered cubic (fcc) and hexagonal close packed (hcp) phases were considered in order to complete a theoretical database of thermodynamic properties. Calculations were done for the ferromagnetic phase, as well as for a phase with local moment disorder, simulating the magnetic structure at high temperatures. For the latter case, the formation energy of the alloy is strictly positive smooth function of chromium concentration, in agreement with experiments performed at high temperature. In the ferromagnetic case, a negative mixing enthalpy is found for chromium concentrations below 6 %. Our observation is consistent with the experimentally observed inversion of the ordering trend, as well as with formation of the chromium rich alpha phase at Cr-concentrations above 9%, occurring at T < 900 K.
Place, publisher, year, edition, pages
2003. Vol. 321, no 1, 84-90 p.
coherent-potential approximation, electronic-structure, computer-simulation, phase-stability, spin dynamics, local order, iron, cu, 1st-principles, fe0.53cr0.47
IdentifiersURN: urn:nbn:se:kth:diva-22774DOI: 10.1016/s0022-3115(03)00207-1ISI: 000185044900010OAI: oai:DiVA.org:kth-22774DiVA: diva2:341472
QC 20100525 NR 201408042010-08-102010-08-102012-01-31Bibliographically approved