Direct Evidence of Anomalous Interfacial Magnetization in Metamagnetic Pd doped FeRh Thin Films

Abstract

Palladium doped iron rhodium is a magnetic material of significant interest for it's close to room temperature magnetostructural phase transition from antiferromagnetic (AF) to ferromagnetic (FM) ordering. Here we report on the peculiarities of the magnetization distribution in thin films of FeRh(Pd) probed by Polarized Neutron Reflectometry. Remarkably, we've found thin interfacial regions with strong magnetization that have unique thermomagnetic properties as compared to the rest of the system. These regions exist at the top and bottom interfaces of the films while the central regions behave similarly to the bulk with a clear AF-FM order transition. Further we explore the impact of an additional Pt interlayer introduced in the middle of the FeRh(Pd) film and reveal that it serves to replicate the strong interfacial magnetization found at the top and bottom interfaces. These results are of great value both in understanding the fundamental physics of such an order transition, and in considering FeRh(Pd) for magnetic media and spintronics applications.

Magnetic order multilayering in FeRh thin films by He-Ion irradiation

“…to be highly controllable by substrate strain [4][5][6][7][8], transition metals substitutional doping [4,5,9,10] and mesoscale patterning [11][12][13][14]. Here, we use low-energy He-ion implantation to precisely tune the metamagnetic transition temperature as a function of ion fluence ( Figure 1(a)).…”

Modeling the thickness dependence of the magnetic phase transition temperature in thin FeRh films

“…Previous studies have shown that it is possible to tune the temperature at which this transition occurs by, for example, varying the composition of iron or rhodium [8], doping with other elements [2,8,9], such as Pd, Pt, or Ir, or straining the sample [10]. Excitation of the phase transition occurs when energy is added to the system allowing one to use a wide range of stimuli to induce the metamagnetic phase transition, such as, electric field [11], temperature [1], applied magnetic fields [12,13], pressure [14], and spin-polarized currents [15] making it a tempting candidate for future magnetic-based technological devices.…”

“…Due to the flexibility in controlling this phase transition, FeRh is undergoing renewed interest [9,[16][17][18] for the development of new devices, such as for low-energy electric-field controlled magnetic recording as an alternative to heat assisted magnetic recording [19], or as a magnetic switch using an exchange-coupled composite [8,20]. For such applications, * thomas.ostler@ulg.ac.be interfacing FeRh with other materials, such as ferromagnets [8] or ferroelectrics [19], is required to functionalize the phase transition.…”

Synthesis of colloidal MnSb nanoparticles: consequences of size and surface characteristics on magnetic properties

“…S1 ESI †) suggests that the reactivity with O is not exclusively occurring with the Mn precursor, but also with the formed MnSb nanocrystals (MnSb + O 2 MnO 2 + Sb). 41 When measured at the saturated level, the ferromagnetic moment of these nanoparticles is approximately 0.04 BM/MnSb, two orders of magnitude smaller than that realized in bulk (3.6 BM/Mn). Indeed, as shown in Fig.…”