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arXiv · 2605.03982

Magneto Transport and Spin Reorientation in Pt Co78Ho22 Heterostructures Near the Sublattice Compensation Temperature

Rajeev Nepal·Jose Flores·Aurain Seaton·Michael Newburger·John Derek Demaree·Ramesh C Budhani
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Abstract

Metallic amorphous ferrimagnets of 3d transition metals (TM) and rare earths (RE) with 4f electrons exhibit rich magneto transport behavior due to the interplay between the 3d and 4f magnetic sublattices and their interaction with mobile charges. Tuning the TM and RE concentrations in the alloy can effectively modulate the compensation temperature, where the moments of the two sublattices point in opposite direction leading to a net zero magnetization. Despite extensive magnetotransport studies in Gd and Tb based 3d 4f systems, Ho based alloys remain comparatively underexplored, even though Ho possesses the largest orbital angular momentum (OAM) among the lanthanides. This unquenched OAM can strongly impact magnetic anisotropy and magnetotransport in ferrimagnetic heterostructures. Here, we have investigated the anomalous Hall resistivity , dc magnetization, and spin Hall magnetoresistance (SHMR) of Co78Ho22.Al film and a Pt.Co78Ho22.Al heterostructure deposited using multitarget magnetron sputtering. The Hall resistivity of both systems shows a distinct sign reversal and prominent wing-shaped hysteresis loops in the vicinity of the compensation temperature (Tcomp), which is accompanied by the minimum saturation magnetization near Tcomp. Furthermore, the SHMR in Pt.Co78Ho22.Al film is enhanced due to the Pt layer. These HM interface-induced prominent features of magneto-transport are addressed in the light of the existing theories of spin flop transitions, spin orbit torque, and microscopic phase separation, which may lead to the formation of 3d and 4f magnetic clusters in the film.

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Rajeev Nepal, Jose Flores, Aurain Seaton, Michael Newburger, John Derek Demaree, Ramesh C Budhani. 2026-05-05. Magneto Transport and Spin Reorientation in Pt Co78Ho22 Heterostructures Near the Sublattice Compensation Temperature. https://arxiv.org/abs/2605.03982

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