Abstract
A real-space TB-LMTO-recursion method for electronic structure calculations is applied to the study of interacting extended and point defects in NiAl. Results of calculations for the pure intermetallic and with ternary additions (within a supercell model) show good agreement with band structure results. Further, electronic structure and total energy calculations of point (single impurity, M=Ti, V, Cr, Mn, Fe and Co) and planar defects such as anti-phase boundaries (APB) were carried out and the interaction between them was determined. We found that for the 1/2 〈111〉 {110} APB in NiAl, ternary additions occupy exclusively the 3d-metal sublattice and decrease the APB energy (except for Co). Finally, we employ TB-LMTO-REC to study the electronic structure of the most complex extended defect, a dislocation. We demonstrate for the 〈100〉 {010} edge dislocation in NiAl that: (i) quasi-localized states may exist as a result of specific lattice distortions in the dislocation core with a type of 'broken' bonds; (ii) the electronic structure changes appreciably in the process of dislocation motion; (iii) van-Hove singularities present in the ideal crystal may be shifted to EF as a result of the dipolar character of the deformations in the dislocation core.
| Original language | English |
|---|---|
| Title of host publication | Materials Research Society Symposium - Proceedings |
| Publisher | MRS |
| Pages | 143-148 |
| Number of pages | 6 |
| Volume | 491 |
| Publication status | Published - 1998 |
| Event | Proceedings of the 1997 MRS Fall Symposium - Boston, MA, USA Duration: Dec 1 1997 → Dec 3 1997 |
Other
| Other | Proceedings of the 1997 MRS Fall Symposium |
|---|---|
| City | Boston, MA, USA |
| Period | 12/1/97 → 12/3/97 |
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ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
Cite this
Interactions of point and extended defects in structural intermetallics : real-space LMTO-recursion calculations. / Kontsevoi, O. Yu; Mryasov, O. N.; Gornostyrev, Yu N.; Freeman, Arthur J.
Materials Research Society Symposium - Proceedings. Vol. 491 MRS, 1998. p. 143-148.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - Interactions of point and extended defects in structural intermetallics
T2 - real-space LMTO-recursion calculations
AU - Kontsevoi, O. Yu
AU - Mryasov, O. N.
AU - Gornostyrev, Yu N.
AU - Freeman, Arthur J
PY - 1998
Y1 - 1998
N2 - A real-space TB-LMTO-recursion method for electronic structure calculations is applied to the study of interacting extended and point defects in NiAl. Results of calculations for the pure intermetallic and with ternary additions (within a supercell model) show good agreement with band structure results. Further, electronic structure and total energy calculations of point (single impurity, M=Ti, V, Cr, Mn, Fe and Co) and planar defects such as anti-phase boundaries (APB) were carried out and the interaction between them was determined. We found that for the 1/2 〈111〉 {110} APB in NiAl, ternary additions occupy exclusively the 3d-metal sublattice and decrease the APB energy (except for Co). Finally, we employ TB-LMTO-REC to study the electronic structure of the most complex extended defect, a dislocation. We demonstrate for the 〈100〉 {010} edge dislocation in NiAl that: (i) quasi-localized states may exist as a result of specific lattice distortions in the dislocation core with a type of 'broken' bonds; (ii) the electronic structure changes appreciably in the process of dislocation motion; (iii) van-Hove singularities present in the ideal crystal may be shifted to EF as a result of the dipolar character of the deformations in the dislocation core.
AB - A real-space TB-LMTO-recursion method for electronic structure calculations is applied to the study of interacting extended and point defects in NiAl. Results of calculations for the pure intermetallic and with ternary additions (within a supercell model) show good agreement with band structure results. Further, electronic structure and total energy calculations of point (single impurity, M=Ti, V, Cr, Mn, Fe and Co) and planar defects such as anti-phase boundaries (APB) were carried out and the interaction between them was determined. We found that for the 1/2 〈111〉 {110} APB in NiAl, ternary additions occupy exclusively the 3d-metal sublattice and decrease the APB energy (except for Co). Finally, we employ TB-LMTO-REC to study the electronic structure of the most complex extended defect, a dislocation. We demonstrate for the 〈100〉 {010} edge dislocation in NiAl that: (i) quasi-localized states may exist as a result of specific lattice distortions in the dislocation core with a type of 'broken' bonds; (ii) the electronic structure changes appreciably in the process of dislocation motion; (iii) van-Hove singularities present in the ideal crystal may be shifted to EF as a result of the dipolar character of the deformations in the dislocation core.
UR - http://www.scopus.com/inward/record.url?scp=0031675645&partnerID=8YFLogxK
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M3 - Conference contribution
AN - SCOPUS:0031675645
VL - 491
SP - 143
EP - 148
BT - Materials Research Society Symposium - Proceedings
PB - MRS
ER -