Field dependent helical magnetic structure in a compensated Gd/Co multilayer

Interface morphology driven exchange interaction and magnetization reversal in a Gd/Co multilayer

“…4(a and b) show the temperature-dependent normalized magnetization [ M ( T )/ M (300 K)] data for the pristine and annealed multilayer, respectively, after zero-field cooling (ZFC, blue open circles) and field cooling (FC, red closed circles) in an in-plane applied field of 500 Oe. The FC M ( T ) data are consistent with the results from other RE/TM multilayers reported earlier, 1,2,6,7,28–31 suggesting temperature-dependent magnetic states and phase transitions. The FC M ( T ) data for both the pristine and annealed multilayer show a minimum in the magnetization at a temperature ( T comp ) of 128 and 150 K, respectively.…”

“…This is also in agreement with the PNR measurements for similarly grown Gd/Co multilayers. 28,30 The PNR data at 300 K show zero magnetization for the Gd layer, which is consistent with the bulk magnetic properties of Gd (Curie temperature ∼293 K). Thus at 300 K, only the Co layer is ferromagnetic for the pristine multilayer, which is consistent with the model, where Co moments are aligned along the field direction.…”

“…6 (m)] suggest a formation of π–3π/2-π and π–0–π rotation of moments along the thickness of the Gd layer at T comp and 5 K, respectively, in the low field (100 Oe), which are in agreement with the magnetization depth profile of a similarly grown Gd/Co multilayer studied by PNR. 28,30,31 At higher field (∼500 Oe) and low temperature (near T comp ), the relatively strong competition between Zeeman and exchange energies result in the formation of almost 2π DW in both the Gd and Co layer for the pristine multilayer [Fig. 6(m)].…”

“…23,24 Thus the spin configurations like helices in the form of planar DW structures with stable magnetic properties in the exchange-coupled RE-TM systems near the compensation temperature is the key to manipulating high-speed magnetic devices. 25–27 Recently the realization of a twisted helical magnetic structure with planar 2π DWs and highly correlated magnetic domains in Gd/Co multilayers 28–31 and other RE-TM systems 5,27,32 has been reported. In addition, a double hysteresis loop (DHL) and an exchange bias (EB) were also observed in these RE-TM heterostructure systems, which was attributed to the depth-dependent magnetic helical structures.…”

“…5,27,28,31,32 The interface structure and morphology have been found to play a vital role in determining the temperature-dependent magnetic configuration and phases in the Gd/TM based multilayers. 6,7,28–31 Here we report the influence of the interface morphology on the evolution of the macroscopic magnetic properties, i.e. , exchange bias field ( E B ), coercive field, compensation temperature ( T comp ), and a vertical shift in the magnetization curve, in the Gd/Co multilayer across the T comp , by combining the experimental methods and theoretical calculations using a one-dimensional-spin based model.…”