Temperature and field dependent magnetization in a sub-μm patterned Co/FeRh film studied by resonant x-ray scattering

Abstract

We studied the temperature and field dependence of the magnetization in a Co/FeRh/MgO(001) film patterned into a matrix of sub-µm sized rectangles, using element selective resonant scattering of polarized soft x-rays. We show that it is possible to reverse partially the magnetization of the Co layer in a thermal cycle that crosses the FeRh antiferromagnetic to ferromagnetic transition. Our results support the interest of patterned Co/FeRh films and their potential for achieving temperature induced magnetization switching.

Magnetization reversal and confinement effects across the metamagnetic phase transition in mesoscale FeRh structures

“…The data in figure 6 allows us to directly follow the magnetization versus temperature behavior for each mesoscale FeRh rectangle in great detail during both the cooling and heating cycles. Metamagnetic behavior in mesoscale FeRh structures has only been studied, so far, via transport measurements [12][13][14]29] or resonant scattering of polarized x-rays [28]. In figures 6(a)-(c), we have also represented the magnetization versus temperature hysteresis loop of the source FeRh film (dashed lines) together with the Kerr microscopy data, from which it is evident that the phase transition of the film is significantly broader when compared to mesoscale structures.…”

FeRh ground state and martensitic transformation

“…The AFM-FM metamagnetic transition is accompanied by a change of Rh moments from 0 to ∼ 1 µ B (FM) [1,4], with large reversible magneto-, baro-, and elasto-caloric effects [12][13][14][15][16][17][18][19], anomalous structural behavior [2,3,25], a giant volume magnetostriction [23], and a giant magnetoresistance [32,50]. This transition temperature is highly sensitive to composition [8,9,35] and external fields [26,[51][52][53][54]. Cooling from a melt, FeRh solidifies at 1600 • C [9], chemically orders into B2 at 1350 • C, magnetically orders into FM at 440 • C and AFM below 80 • C, and transforms into a martensite at a cryogenic temperature.…”

Layer-sensitive magneto-optical Kerr effect study of magnetization reversal in Fe/MnAs/GaAs(001)

“…25,29 In this respect, it may be applied to Co/FeRh bilayers in order to study the temperature-dependent coupling arising from the antiferromagnetic-ferromagnetic phase transition in FeRh. 30 Concerning the limitations of the technique, it should be noted that, if it works well for the acquisition of magnetic cycles, temperature or time dependent measurements with layer resolution can be more involved and element-selectivity remains a major asset.…”