Post Deposition Interfacial Néel Temperature Tuning in Magnetoelectric B:Cr2O3

Published

January 28, 2024

Author(s)

Ather Mahmood, Jamie Weaver, Will Echtenkamp, Syed Qamar Abbas Shah, Jeffrey Lynn, Christian Binek

Abstract

Boron (B) alloying transforms the magnetoelectric antiferromagnet Cr2O3 into a multifunctional single-phase material which enables electric field driven /2 rotation of the Néel vector. Nonvolatile, voltage-controlled Néel vector rotation is a much-desired material property in the context of antiferromagnetic spintronics enabling ultralow power, ultrafast, nonvolatile memory, and logic device applications. Néel vector rotation is detected with the help of heavy metal (Pt) Hall-bars in proximity of pulsed laser deposited B:Cr2O3 films. To facilitate operation of B:Cr2O3-based devices in CMOS (complementary metal-oxide semiconductor) environments, the Néel temperature, TN, of the functional film must be tunable to values significantly above room temperature. Cold neutron depth profiling and X-ray photoemission spectroscopy depth profiling reveal thermally activated B-accumulation at the B:Cr2O3/ vacuum interface in thin films deposited on Al2O3 substrates. The B-enrichment is attributed to surface segregation. Magnetotransport data confirm B-accumulation at the interface within a layer of ≈50 nm thick where the device properties reside. Here TN enhances from 334 K prior to annealing, to 477 K after annealing for several hours. Scaling analysis determines TN as a function of the annealing temperature. Stability of post-annealing device properties is evident from reproducible Néel vector rotation at 370 K performed over the course of weeks.

Citation

Advanced Physics Research

Volume

3

Issue

1

Pub Type

Journals

Download Paper

https://doi.org/10.1002/apxr.202470001

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Keywords

spintronics, Néel vector, neutron depth profiling

Citation

Mahmood, A. , Weaver, J. , Echtenkamp, W. , Abbas Shah, S. , Lynn, J. and Binek, C. (2024), Post Deposition Interfacial Néel Temperature Tuning in Magnetoelectric B:Cr2O3, Advanced Physics Research, [online], https://doi.org/10.1002/apxr.202470001, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=935154 (Accessed November 28, 2025)