Angle dependent magnetoresistance in heterostructures with antiferromagnetic and non-magnetic metals

Abstract

We report on the magnetoresistive effects in a metallic antiferromagnet (AFM)/nonmagnet (NM) PtMn/Pt heterostructure with varying thickness of PtMn (1 nm ≤ tPtMn ≤ 10 nm). Longitudinal magnetoresistive effects are measured for magnetic field rotations along three mutually perpendicular directions. The results show a transformation in the functional dependencies with the increase in tPtMn and are attributed to the spin Hall magnetoresistive effects arising from the interaction of spin currents generated by Pt with the antiferromagnetic PtMn. The present findings with appreciable magnetoresistive effects in an AFM/NM metallic heterostructure add yet another option of the material system for antiferromagnetic spintronics.

Spin-orbit torque switching of an antiferromagnetic metallic heterostructure

“…After the fabrication, the samples were annealed at 300 °C for two hours under an in-plane magnetic field of 1.2 T directed parallel to the write channel. Resistivities of Ta, Pt, and Pt 0.38 Mn 0.62 layers were determined from separate measurements of sheet resistance on annealed blanket films and is reported elsewhere 17 .…”

“…corresponds to a class of specialized material, traditionally utilized in spin-valve structures owing to its capabilities of significant exchange bias field, low processing temperatures, and compatibility with Si-based electronics. The favorable combination of room temperature ordering 29 , 30 , high thermal stability 31 , significant bulk uniaxial magnetic anisotropy 32 , and magnetoresistive effects in PtMn for reading 17 renders this material feasible for future antiferromagnetic spintronic devices.…”

“…Figure 1(c)–(f) schematically shows the sequence of electrical measurements. Electrical writing of information is achieved by sourcing pulsed currents ( I 1,2 ) along two orthogonal directions (A(C)→B(D)) while the corresponding resistance state is read-out by measuring the transverse Hall resistance ( R Hall ) of the sample using a dc current ( I DC ) of much weaker amplitude than I 1,2 17 . A waiting time of 10 s is employed after each write pulse.…”

“…To achieve this objective, the capability to electrically record and retrieve information from an antiferromagnetic material is of paramount importance. Previous works investigated the interaction of current with the antiferromagnetic Néel vector (staggered moment) resulting in anisotropic and spin-Hall magnetoresistance (SMR) effects [14][15][16][17] , which can serve as an electrical probe for reading. Switching of an AFM either by field-like Néel SOTs originating from inverse spin galvanic effects 7,[18][19][20][21] or SOTs in AFM-insulator/heavy metal (HM) heterostructures [22][23][24] and electric field control of Néel SOTs 25 have been demonstrated, offering techniques to manipulate antiferromagnetic Néel vector.…”

Epitaxial growth, structural characterization, and exchange bias of noncollinear antiferromagnetic Mn3Ir thin films

“…Motivated by these improvements in performance, the field of antiferromagnetic spintronics has rapidly grown [9], investigating a range of different materials. More recent experimental observations include spin-orbit torque switching and electrical read-out of the AF state in CuMnAs [10], Mn2Au [11] and MnTe [12], as well as spin currents and spin Hall magnetoresistance effects in PtMn [13,14]. Understanding of AF domain structure is important for the efficient control of the above effects in these metallic materials, all of which exhibit collinear AF order.…”