Calculations of giant magnetoresistance in Fe/Cr trilayers using layer potentials determined fromab initiomethods

Abstract

The ab initio full-potential linearized augmented plane-wave method explicitly designed for the slab geometry was employed to elucidate the physical origin of the layer potentials for the trilayers nFe/3Cr/nFe(001), where n is the number of Fe monolayers. The thickness of the transition-metal ferromagnet has been ranged from n = 1 up to n = 8 while the spacer thickness was fixed to 3 monolayers. The calculated potentials were inserted in the Fuchs-Sondheimer formalism in order to calculate the giant magnetoresistance (GMR) ratio. The predicted GMR ratio was compared with the experiment and the oscillatory behavior of the GMR as a function of the ferromagnetic layer thickness was discussed in the context of the layer potentials. The reported results confirm that the interface monolayers play a dominant role in the intrinsic GMR.

Giant magnetoresistance in spin valves realized by substituting Y-site atoms in Heusler lattice

“…While, MR p can directly reflect the spin-resolved interfacial scattering which dominates the electronic transport properties [57]. Then, a SV effect is reported that in metal layers, the interfacial scattering can either enhance or degrade MR p [58]. In our case, due to band match between the components of SV, T ↓ p , T ↑ ap and T ↓ ap at E F are almost zero which means the spin-resolved interfacial scattering can enhance MR p to almost 100%.…”

Magnetic and electronic structure of nFe/3Cr/nFe slabs (n = 1 → 6)

“…Even though the generalized gradient approximation provides more accurate results, Herper et al verified that this is due to a better geometry optimization [11]. Since the atomic positions are well known for our systems, LSDA is adequate [12]. The crystalline structure of our system is going to be considered as body-centered cubic (bcc), fitting with the known crystalline structures of both Fe and Cr bulk metals [13].…”

“…For thin layers, it is reported that for 3ML, the stable Cr structure is an unstrained bcc [14]. Furthermore, we assume that the bcc structure is going to be held all along the system with the same lattice constant: α = 2.88Å, because it has been found that the difference between studying the system using both lattice constants for each respective metal slab, and using only one for both metals, is negligible [12]. For the above reasons, we are not going to allow any relaxation of the structure.…”

The Magnetic Equation of State and Transport Properties in Reduced Dimensions

“…The resistance of the single thin metallic layers was calculated lately by Paja and co-workers [2,3] for the binary and ternary alloys [4,5]. The transport properties for trilayers and multilayers were considered in [6].…”