Title: Hydration of gadolinium oxide ( $\mathrm{Gd}{\mathrm{O}}_x$ ) and its effect on voltage-induced Co oxidation in a $\mathrm{Pt}/\mathrm{Co}/\mathrm{Gd}{\mathrm{O}}_x/\mathrm{Au}$ heterostructure

Abstract

Magneto-ionic control of magnetism has garnered great interest in recent years due to the large magnetic changes that can be induced using a relatively small voltage. One model structure for this is Pt/Co/GdO_x/Au , where Co is the magnetic layer and GdO_x is the ionic conductor, with the magnetic properties dependent on the oxidation state of Co. While this structure is commonly used, there is limited understanding of the effect of GdO_x properties on voltage-induced magnetic changes. In this work, we show that hydration of Gd₂O₃ to form Gd(OH)₃ is crucial for voltage-induced Co oxidation in a Pt/Co/GdO_x/Au device. By examining the rate of Co oxidation in nonhydrated and hydrated devices, we conclude that H₂O in the GdO_x layer acts as an oxidant during the voltage-induced Co oxidation process. Co oxidation through this interfacial reaction process is confirmed by in situ x-ray absorption spectroscopy.

Authors:

Tan, Aik Jun ^[1]; Huang, Mantao ^[1]; Sheffels, Sara ^[1]; Büttner, Felix ^[2]; Kim, Sunho ^[1]; Hunt, Adrian H. ^[3]; Waluyo, Iradwikanari ^[3]; Tuller, Harry L. ^[1]; Beach, Geoffrey S. D. ^[1]

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+ Show Author Affiliations

1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
2. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source II (NSLS-II)
3. Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source II (NSLS-II)

Publication Date:

2019-06-17

Research Org.:

Brookhaven National Lab. (BNL), Upton, NY (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1543413

Alternate Identifier(s):

OSTI ID: 1526659

Report Number(s):

BNL-211908-2019-JAAM
Journal ID: ISSN 2475-9953; PRMHAR

Grant/Contract Number:  

SC0012704

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review Materials

Additional Journal Information:

Journal Volume: 3; Journal Issue: 6; Journal ID: ISSN 2475-9953

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE