Enhanced spin-orbit torque by engineering Pt resistivity in Pt/Co/Al Ox structures

Jae Wook Lee, Young Wan Oh, Seung Young Park, Adriana I. Figueroa, Gerrit Van Der Laan, Gyungchoon Go, Kyoung Jin Lee, Byong Guk Park

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28 Citations (Scopus)

Abstract

The magnetization direction in heavy-metal (HM)/ferromagnet bilayers can be electrically controlled by spin-orbit torque (SOT); however, the efficiency of the SOT which depends on the spin-orbit coupling of the HM layer or its spin-Hall angle has to be improved further for actual applications. In this study, we report a significant enhancement of the spin-Hall effect of Pt and resultant SOT in Pt/Co/AlOx structures by controlling the Pt resistivity. We observed that the effective spin-Hall angle increases about three times as the resistivity of Pt layer is increased 1.6 times by changing the Ar deposition pressure from 3 to 50 mTorr. This enhancement in effective spin-Hall angle is confirmed by the reduction in the critical current for SOT-induced magnetization switching. Furthermore, x-ray absorption spectroscopy analysis reveals a non-negligible contribution of the interfacial spin-orbit coupling to the effective spin-Hall angle. Our result, the efficient control of effective spin Hall angle by controlling the HM resistivity, paves the way to improved switching efficiency in SOT-active devices.

Original languageEnglish
Article number064405
JournalPhysical Review B
Volume96
Issue number6
DOIs
Publication statusPublished - 2017 Aug 3

ASJC Scopus subject areas

  • Condensed Matter Physics

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    Lee, J. W., Oh, Y. W., Park, S. Y., Figueroa, A. I., Van Der Laan, G., Go, G., Lee, K. J., & Park, B. G. (2017). Enhanced spin-orbit torque by engineering Pt resistivity in Pt/Co/Al Ox structures. Physical Review B, 96(6), [064405]. https://doi.org/10.1103/PhysRevB.96.064405