TY - GEN
T1 - CVM-based first-principles calculations for Fe-based alloys
AU - Mohri, Tetsuo
N1 - Funding Information:
The present work was partly supported by Next Generation Supercomputing Project, Nanoscience Program, MEXT, Japan. The author is very grateful to Professors M. Ohno of Hokkaido University and Y. Chen of Tohoku University for their stimulating discussions and cooperations throughout this work.
PY - 2011
Y1 - 2011
N2 - Cluster Variation Method (CVM) has been recognized as one of the most reliable theoretical tools to incorporate wide range of atomic correlations into a free energy formula. By combining CVM with electronic structure total energy calculations, one can perform first-principles calculations of alloy phase equilibria. The author attempted such CVM-based first-principles calculations for various alloy systems including noble metal alloys, transition-noble alloys, III-V semiconductor alloys and Fe-based alloy systems. Furthermore, CVM can be extended to two kinds of kinetics calculations. One is Path Probability Method (PPM) which is the natural extension of the CVM to time domain and is quite powerful to investigate atomistic kinetic phenomena. The other one is Phase Field Method (PFM) with the CVM free energy as a homogeneous free energy density term in the PFM. The author's group applied the latter procedure to study time evolution process of ordered domains associated with disorder-L1 0 transition in Fe-Pd and Fe-Pt systems. CVM has, therefore, a potential applicability for the systematic studies covering atomistic to microstructural scales. It has been, however, pointed out that the conventional CVM is not able to include local lattice relaxation effects and that the resulting order-disorder transition temperatures are overestimated. In order to circumvent such inconveniences, Continuous Displacement Cluster Variation Method (CDCVM) has been developed. Since first-principles CDCVM calculations are still beyond the scope at the present stage, preliminary results on the two dimensional square lattice and an fee lattice with primitive Lennard-Jones type potentials are demonstrated in the last section.
AB - Cluster Variation Method (CVM) has been recognized as one of the most reliable theoretical tools to incorporate wide range of atomic correlations into a free energy formula. By combining CVM with electronic structure total energy calculations, one can perform first-principles calculations of alloy phase equilibria. The author attempted such CVM-based first-principles calculations for various alloy systems including noble metal alloys, transition-noble alloys, III-V semiconductor alloys and Fe-based alloy systems. Furthermore, CVM can be extended to two kinds of kinetics calculations. One is Path Probability Method (PPM) which is the natural extension of the CVM to time domain and is quite powerful to investigate atomistic kinetic phenomena. The other one is Phase Field Method (PFM) with the CVM free energy as a homogeneous free energy density term in the PFM. The author's group applied the latter procedure to study time evolution process of ordered domains associated with disorder-L1 0 transition in Fe-Pd and Fe-Pt systems. CVM has, therefore, a potential applicability for the systematic studies covering atomistic to microstructural scales. It has been, however, pointed out that the conventional CVM is not able to include local lattice relaxation effects and that the resulting order-disorder transition temperatures are overestimated. In order to circumvent such inconveniences, Continuous Displacement Cluster Variation Method (CDCVM) has been developed. Since first-principles CDCVM calculations are still beyond the scope at the present stage, preliminary results on the two dimensional square lattice and an fee lattice with primitive Lennard-Jones type potentials are demonstrated in the last section.
UR - http://www.scopus.com/inward/record.url?scp=84859098445&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84859098445&partnerID=8YFLogxK
U2 - 10.1557/opl.2011.1451
DO - 10.1557/opl.2011.1451
M3 - Conference contribution
AN - SCOPUS:84859098445
SN - 9781618395092
T3 - Materials Research Society Symposium Proceedings
SP - 99
EP - 109
BT - New Methods in Steel Design - Steel Ab Initio
T2 - 2010 MRS Fall Meeting
Y2 - 29 November 2010 through 3 December 2010
ER -