TY - JOUR
T1 - Energetics of C11b, C40, C54, and C49 structures in transition-metal disilicides
AU - Carlsson, A. E.
N1 - Funding Information:
We are grateful to Art Williams and Victor Moruzzi for supplying a copy of the ASW code developed at IBM, and to Jurgen Kiibler for the use of relativistic corrections to that code. This research was supported by the McDonnell Douglas Independent Research and Development Program. The total-energy calculations were performed at the Production Supercomputer Facility of the Center for Theory and Simulation at Cornell University, under National Science Foundation Grant No. DMR-8614232.
PY - 1991/7
Y1 - 1991/7
N2 - The relative energies of the related C11b, C40, and C54 crystal structures of group IV-VII transition-metal disilicides are obtained by ab initio self-consistent band-structure calculations using the augmented-spherical-wave (ASW) method. The structural energy differences among these three structures correlate strongly with d-band filling, with C40 being stabilized relative to C54 and C11b relative to C40 as the transition-metal d-electron count increases. The C40/C11b energy difference is <0.05 eV/atom only for CrSi2 and MoSi2. Relative C11b/C40/C54 energies are similar in magnitude to those obtained in previous studies of Ll2/D022/D023 competition in transition-metal aluminides.1,2 Calculations of the C49/C54 energetic competition are inaccurate; the differences in atomic coordination in these two structures are probably too large for the computational method to handle accurately. The total-energy results are interpreted by a detailed analysis of the electronic density-of-states (DOS) distributions. The stable structures do not correlate as strongly with DOS effects in the vicinity of the Fermi level as in the aluminides.
AB - The relative energies of the related C11b, C40, and C54 crystal structures of group IV-VII transition-metal disilicides are obtained by ab initio self-consistent band-structure calculations using the augmented-spherical-wave (ASW) method. The structural energy differences among these three structures correlate strongly with d-band filling, with C40 being stabilized relative to C54 and C11b relative to C40 as the transition-metal d-electron count increases. The C40/C11b energy difference is <0.05 eV/atom only for CrSi2 and MoSi2. Relative C11b/C40/C54 energies are similar in magnitude to those obtained in previous studies of Ll2/D022/D023 competition in transition-metal aluminides.1,2 Calculations of the C49/C54 energetic competition are inaccurate; the differences in atomic coordination in these two structures are probably too large for the computational method to handle accurately. The total-energy results are interpreted by a detailed analysis of the electronic density-of-states (DOS) distributions. The stable structures do not correlate as strongly with DOS effects in the vicinity of the Fermi level as in the aluminides.
UR - http://www.scopus.com/inward/record.url?scp=0026187872&partnerID=8YFLogxK
U2 - 10.1557/JMR.1991.1512
DO - 10.1557/JMR.1991.1512
M3 - Article
AN - SCOPUS:0026187872
SN - 0884-2914
VL - 6
SP - 1512
EP - 1517
JO - Journal of Materials Research
JF - Journal of Materials Research
IS - 7
ER -