Magnetization reversal and magnetic interactions in patterned spin valve structures

Abstract

We have investigated the magnetization reversal and the magnetic anisotropy of epitaxial Co(1 12 0) and Fe(0 0 1) films and compared them with epitaxial Co(1 12 0)/Cr(0 0 1)/Fe(0 0 1) trilayers with spin valve characteristics. Furthermore, by e-beam lithography we have cut the single layers and the trilayers into the shape of wires to study the effect of the shape anisotropy and the dipolar interaction between the wires on their switching characteristics. We found that patterning very much affects the magnetization reversal of the single films by introducing an additional anisotropy term. Dipolar interaction between the different wires may exist but is less obvious. However, the remagnetization process of the patterned trilayers resembles more those of the continuous single films than a combination of the Co and Fe wires. We argue that this is due to a weak but remaining interlayer exchange coupling between Co and Fe, mediated by the intervening Cr layer.

Laterally patterned spin-valve superlattice: Magnetometry and polarized neutron scattering study

“…29,30 The asymmetric superlattice consists of two different ferromagnetic layers with a total of eight repetitions and a layer sequence of [Fe/Cr/Co/Cr] Â 8 with nominal thicknesses according to the values in Table I. The sample was grown at a temperature of 300 C on MgO(100) single crystal substrates by use of a 25 nm thick Cr(100) buffer layer deposited at substrate temperature of 600 C. More details of the sample growth conditions can be found in Ref.…”

“…The sample was grown at a temperature of 300 C on MgO(100) single crystal substrates by use of a 25 nm thick Cr(100) buffer layer deposited at substrate temperature of 600 C. More details of the sample growth conditions can be found in Ref. 29. The thickness of the Cr interlayers was chosen to mediate a weak antiferromagnetic (AF) coupling between the Fe and the Co layers, as reported in Ref.…”

Direct observation of Cr spin polarization in epitaxial Cr/Co/Cr(100) trilayers

“…[32][33][34] For the more general magnetic properties of the trilayer including magnetic hysteresis measurements we refer to our earlier study reported in Ref. 25.…”

Magnetization and magnetization reversal in epitaxial Fe/Cr/Co asymmetric spin-valve systems

“…The present study amends earlier investigations of Co/Cr/Fe trilayers via the magnetooptic Kerr effect (MOKE). 18,19 In these previous studies, we have established the range of interlayer exchange coupling between Fe and Co layers across the mediating Cr layer 18 and the magnetization reversal process of single Fe and Co layers as compared to the coupled layers using vector MOKE. 19 Before we discuss our present results in Secs.…”