First principles calculations of the electronic and geometric structure of $Ag_{27}Cu_{7}$ nanoalloy

Details First principles calculations of the electronic and geometric structure of $Ag_{27}Cu_{7}$ nanoalloy First principles calculations of the electronic and geometric structure of $Ag_{27}Cu_{7}$ nanoalloy

2008-02-21

arxiv.org/abs/0802.2987v1

Physics

Condensed Matter

Materials Science

16 figures

Scientific paper

10.1103/PhysRevB.77.195404

\emph{Ab initio} calculations of the structure and electronic density of states (DOS) of the perfect core-shell $Ag_{27}Cu_{7}$ nanoalloy attest to its $D_{5h}$ symmetry and confirm that it has only 6 non-equivalent (2 $Cu$ and 4 $Ag$) atoms. Analysis of bond-length, average formation energy, heat of formation of $Ag_{27}Cu_{7}$ and $L1_2$ $Ag-Cu$ alloys provide an explanation for the relative stability of the former with respect to the other nanoalloys in the same family. The HOMO-LUMO gap is found to be 0.77 eV, in agreement with previous results. Analysis of the DOS of $Ag_{27}Cu_{7}$, $L1_2$ $Ag-Cu$ alloys and related systems provides insight into the effects of low coordination, contraction/expansion and the presence of foreign atoms on the DOS of $Cu$ and $Ag$. While some characteristics of the DOS are reminiscent of those of the phonon-stable $L1_2$ $Ag-Cu$ alloys, the $Cu$ and $Ag$ states hybridize significantly in $Ag_{27}Cu_{7}$, compensating the $d$-band narrowing that each atom undergoes and hindering the dip in the DOS found in the bulk alloys. Charge density plots of $Ag_{27}Cu_{7}$ provide further insights into the relative strengths of the various interatomic bonds. Our results for the electronic and geometric structure of this nanoalloy can be explained in terms of length and strength hierarchies of the bonds, which may have implications also for the stability of alloy in any phase or size.

Affiliated with

Also associated with

No associations

Rating

First principles calculations of the electronic and geometric structure of $Ag_{27}Cu_{7}$ nanoalloy does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with First principles calculations of the electronic and geometric structure of $Ag_{27}Cu_{7}$ nanoalloy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and First principles calculations of the electronic and geometric structure of $Ag_{27}Cu_{7}$ nanoalloy will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-578453