Abstract
The nature of the unusual mechanical properties of Ir in comparison with other fcc metals (brittle failure after a long stage of plastic deformation) is investigated on the basis of ab initio total energy local density calculations. The structure and energy characteristics of defects (vacancies, dislocation cores, stacking faults) as well as decohesion curves are calculated for Ir, and their peculiarities are discussed in comparison with results for a typical ductile metal Au. The chemical bonding of Ir in comparison with Pt and Au is considered based on the calculated charge density maps and tight-binding parameters. It is shown that the appearance of a "pseudocovalent" component of the chemical bonding in Ir under shear deformation leads to unusually large values of its shear moduli, which is the final cause of its brittleness, according to the standard criteria of brittle-ductile behavior.
| Original language | English |
|---|---|
| Pages (from-to) | 7802-7808 |
| Number of pages | 7 |
| Journal | Physical Review B - Condensed Matter and Materials Physics |
| Volume | 62 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - Sep 15 2000 |
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ASJC Scopus subject areas
- Condensed Matter Physics
Cite this
Peculiarities of defect structure and mechanical properties of iridium : Results of ab initio electronic structure calculations. / Gornostyrev, Yu N.; Katsnelson, M. I.; Medvedeva, N. I.; Mryasov, O. N.; Freeman, Arthur J; Trefilov, A. V.
In: Physical Review B - Condensed Matter and Materials Physics, Vol. 62, No. 12, 15.09.2000, p. 7802-7808.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Peculiarities of defect structure and mechanical properties of iridium
T2 - Results of ab initio electronic structure calculations
AU - Gornostyrev, Yu N.
AU - Katsnelson, M. I.
AU - Medvedeva, N. I.
AU - Mryasov, O. N.
AU - Freeman, Arthur J
AU - Trefilov, A. V.
PY - 2000/9/15
Y1 - 2000/9/15
N2 - The nature of the unusual mechanical properties of Ir in comparison with other fcc metals (brittle failure after a long stage of plastic deformation) is investigated on the basis of ab initio total energy local density calculations. The structure and energy characteristics of defects (vacancies, dislocation cores, stacking faults) as well as decohesion curves are calculated for Ir, and their peculiarities are discussed in comparison with results for a typical ductile metal Au. The chemical bonding of Ir in comparison with Pt and Au is considered based on the calculated charge density maps and tight-binding parameters. It is shown that the appearance of a "pseudocovalent" component of the chemical bonding in Ir under shear deformation leads to unusually large values of its shear moduli, which is the final cause of its brittleness, according to the standard criteria of brittle-ductile behavior.
AB - The nature of the unusual mechanical properties of Ir in comparison with other fcc metals (brittle failure after a long stage of plastic deformation) is investigated on the basis of ab initio total energy local density calculations. The structure and energy characteristics of defects (vacancies, dislocation cores, stacking faults) as well as decohesion curves are calculated for Ir, and their peculiarities are discussed in comparison with results for a typical ductile metal Au. The chemical bonding of Ir in comparison with Pt and Au is considered based on the calculated charge density maps and tight-binding parameters. It is shown that the appearance of a "pseudocovalent" component of the chemical bonding in Ir under shear deformation leads to unusually large values of its shear moduli, which is the final cause of its brittleness, according to the standard criteria of brittle-ductile behavior.
UR - http://www.scopus.com/inward/record.url?scp=0034664649&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034664649&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.62.7802
DO - 10.1103/PhysRevB.62.7802
M3 - Article
AN - SCOPUS:0034664649
VL - 62
SP - 7802
EP - 7808
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 1098-0121
IS - 12
ER -