Magnetization in quasiperiodic magnetic multilayers with biquadratic exchange coupling

Abstract

A theoretical study of the magnetization curves of quasiperiodic magnetic multilayers is presented. We consider structures composed by ferromagnetic films (Fe) with interfilm exchange coupling provided by intervening nonferromagnetic layers (Cr). The theory is based on a realistic phenomenological model, which includes the following contributions to the free magnetic energy: Zeeman, cubic anisotropy, bilinear and biquadratic exchange energies. The experimental parameters used here are based on experimental data recently reported, which contain sufficiently strong biquadratic exchange coupling.

Theoretical and experimental study of Fe/Cr nanometric quasiperiodic multilayers

“…The equilibrium positions of the magnetizations {θ i } are numerically calculated by minimizing the magnetic energy given by Eq. (2) [13,14].…”

“…In fact, it is now possible to ''tailor'' multilayers with very specific properties. Considering this aspect, the physical properties of a new class of magnetic system, namely quasiperiodic magnetic multilayers, became an attractive field of research [12][13][14][15][16]. In this communication we report an experimental and theoretical investigation on the magnetic properties of periodic and quasiperiodic Fe/Cr (100) Hereafter we follow the lines of Refs.…”

“…We should remark that, as shown in Refs. [13,14], the effects of the quasiperiodic order on the physical properties of Fe/Cr magnetic multilayers reveal magnetic phases and alignments that are only due to the quasiperiodicity of the system. In particular, the self-similarity of the physical observables (magnetoresistance and magnetization curves), which is the basic signature of quasiperiodic order, emerges even for a small number of layers (see for example Fig.…”

“…5 (see Refs. [14,19]). There are two magnetic phases: (i) 90°(0 < H < 70 Oe) and (ii) saturated (H > 70 Oe).…”

“…In this communication we report an experimental and theoretical investigation on the magnetic properties of periodic and quasiperiodic Fe/Cr (100) Hereafter we follow the lines of Refs. [13,14]. Theoretically, a quasiperiodic structure is constructed juxtaposing two building blocks (or layers) following a given quasiperiodic sequence.…”