Eur. Phys. J. D (2015) 69: 51
https://doi.org/10.1140/epjd/e2015-50804-6

Regular Article

Stable geometries and magnetic properties of neutral Sn_x+1 and FeSn_x (x ≤ 8) clusters

¹ Facultad de Ciencias, Universidad Autónoma de San Luis Potosí, Álvaro Obregón 64, 78000 San Luis Potosí, Mexico
² Doctorado Institucional en Ciencia e Ingeniería de Materiales, Universidad Autónoma de San Luis Potosí, Álvaro Obregón 64, 78000 San Luis Potosí, Mexico
³ Instituto de Física ‘Manuel Sandoval Vallarta’, Universidad Autónoma de San Luis Potosí, Álvaro Obreón 64. 78000 San Luis Potosí, Mexico

^a e-mail: jmmc@dec1.ifisica.uaslp.mx

Received: 8 November 2014
Received in final form: 7 January 2015
Published online: 19 February 2015

Abstract

We report the results of calculations which were performed to investigate the magnetic properties and energetic properties of equilibrium structures of small FeSn_x (x = 1–8) clusters, within the framework of the density functional theory by using the SIESTA code. The presence of the Fe impurity modifies the equilibrium geometries and the spin state of the free Sn clusters. All the FeSn clusters present magnetic order and show a dependence with the concentration x; in some cases the magnetic order into the cluster is ferromagnetic-like, generally the magnetic coupling in Sn atoms is ferromagnetic-like but our results show than in some clusters coexist the antiferromagnetic-like order with the ferromagnetic-like order in the Sn atoms. We have studied the fragmentation of the clusters and our results show the absence of a predominant fragmentation channel. The presence of the impurity induces a low value of HOMO-LUMO gap with respect to free Sn clusters.