Unraveling the effect of oxygen on the magnetic map of Fe/Cr multilayers
- PDF / 403,362 Bytes
- 4 Pages / 595.276 x 785.197 pts Page_size
- 63 Downloads / 173 Views
THE EUROPEAN PHYSICAL JOURNAL B
Regular Article
Unraveling the effect of oxygen on the magnetic map of Fe/Cr multilayers Salvador Meza-Aguilar 1,a and Claude Demangeat 2 1
2
Facultad de Ciencias F´ısico-Matem´ aticas de la Universidad Aut´ onoma de Sinaloa, Av. Las Americas y Blvd. Universitarios, Colonia Universitaria, C. P. 80010, Culiac´ an Sinaloa, Mexico UFR de Physique et d’Ing´enierie, 3 rue de l’Universit´e, 67000 Strasbourg, France Received 17 January 2020 / Received in final form 28 April 2020 Published online 10 June 2020 c EDP Sciences / Societ`
a Italiana di Fisica / Springer-Verlag GmbH Germany, part of Springer Nature, 2020 Abstract. Recent experimental results have depicted a strong modification of the magnetic map when oxygen is added to Fe/Cr multilayers. Within ab initio DFT + U code we show that the Fe/O/Cr/Fe(001) semi-infinite system is unstable whereas oxygen tends to move on top of the Fe atomic layer. Focuss is therefore made on the O/Fe/Cr/Fe(001) semi-infinite slab which displays an interlayer exchange coupling different from the classical case when O is absent. The effect of the oxygen adsorbed layer is to alter strongly the local density of states on the Fe atoms: this can explain the modification of the interlayer exchange coupling. Both DFT-only and DFT + U approaches are investigated in order to point out the major effect of U on the magnetic polarization.
1 Introduction Baibich et al. [1] as well as Binasch et al. [2] have depicted giant magnetoresistance and interlayer exchange coupling (IEC) in Fe/Cr superlattices. This IEC was explained by Stoeffler and Gautier [3], Herman et al. [4] and Vega et al. [5] via semi-empirical tight-binding and ab initio methods. Within semi-empirical tight-binding method limited to d -orbitals, Stoeffler and Gautier [3] have obtained an IEC with an oscillatory period of 2 monolayers in Fe/Cr superlattices. Such result has been confirmed by Herman et al. [4] via ab initio code (LMTO-ASA and LASW-ASA). Similarly Vega et al. [5] via semi-empirical spd-tight binding code have depicted antiferromagntic coupling at the Fe/Cr and Fe/V multilayers. Moreover for Fe/Crn /Fe(001) Vega et al. [5] have found a ferromagnetic coupling between the Fe surface and the Fe substrate when n is odd whereas an antiferromagnetic coupling is obtained when n is even (n is the number of Cr interlayers). Very recently, Lebrun et al. [6] have obtained longdistance transport of electron-spin in an antiferromagnet (Rezende [7]). This antiferromagnet is essentially an Feoxide. Recently Calloni et al. [8] have studied the oxidation of a Cr film deposited on Fe(001) substrate. They have also calculated the electronic, magnetic and structural properties of various CrO oxides on Fe(001). Those calculations were performed with Quantum Expresso [9] code (QEC). This QEC code contains a version valid for metallic systems (that used by Picone et al. [10,11]) and a DFT + U version valid for oxide materials. In a recent paper [12] a
e-mail: [email protected]
we have focused on CrO laye
Data Loading...
