The impact of Hf layer thickness on the perpendicular magnetic anisotropy in Hf/CoFeB/MgO/Ta films

Minghua Li; Jinhui Lu; Mustafa Akyol; Xi Chen; Hui Shi; Gang Han; Tong Shi; Guanghua Yu; Ahmet Ekicibil; Nick Kioussis; P. V. Ong; Pedram Khalili Amiri; Kang L. Wang

doi:10.1016/j.jallcom.2016.09.309

The impact of Hf layer thickness on the perpendicular magnetic anisotropy in Hf/CoFeB/MgO/Ta films

Minghua Li^*, Jinhui Lu, Mustafa Akyol, Xi Chen, Hui Shi, Gang Han, Tong Shi, Guanghua Yu, Ahmet Ekicibil, Nick Kioussis, P. V. Ong, Pedram Khalili Amiri, Kang L. Wang

^*Corresponding author for this work

Electrical and Computer Engineering

Research output: Contribution to journal › Article › peer-review

9 Scopus citations

Abstract

The impact of Hf layer thickness on magnetic anisotropy is evaluated for Hf/CoFeB/MgO/Ta multilayer films commonly used in magnetic tunnel junctions (MTJs). An easy-axis magnetization transition from the in-plane to the out-of-plane direction is observed when the thickness of Hf is greater than ∼1.5 nm in our structure. Moreover, a critical Hf layer thickness exists for strong perpendicular magnetic anisotropy on the CoFeB/MgO interface that maintains the properties required for use in MTJs. We also perform X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD) to study the effects of film composition, chemical states, and crystallization on the magnetic anisotropy in Hf/FeCoB/MgO/Ta multilayers with Hf layers of various thicknesses.

Original language	English (US)
Pages (from-to)	76-81
Number of pages	6
Journal	Journal of Alloys and Compounds
Volume	694
DOIs	https://doi.org/10.1016/j.jallcom.2016.09.309
State	Published - 2017

Keywords

CoFeB
Hf
Perpendicular magnetic anisotropy

ASJC Scopus subject areas

Mechanics of Materials
Mechanical Engineering
Metals and Alloys
Materials Chemistry

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10.1016/j.jallcom.2016.09.309

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@article{d3aac01b48ca4bebb83bd71605dc896a,

title = "The impact of Hf layer thickness on the perpendicular magnetic anisotropy in Hf/CoFeB/MgO/Ta films",

abstract = "The impact of Hf layer thickness on magnetic anisotropy is evaluated for Hf/CoFeB/MgO/Ta multilayer films commonly used in magnetic tunnel junctions (MTJs). An easy-axis magnetization transition from the in-plane to the out-of-plane direction is observed when the thickness of Hf is greater than ∼1.5 nm in our structure. Moreover, a critical Hf layer thickness exists for strong perpendicular magnetic anisotropy on the CoFeB/MgO interface that maintains the properties required for use in MTJs. We also perform X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD) to study the effects of film composition, chemical states, and crystallization on the magnetic anisotropy in Hf/FeCoB/MgO/Ta multilayers with Hf layers of various thicknesses.",

keywords = "CoFeB, Hf, Perpendicular magnetic anisotropy",

author = "Minghua Li and Jinhui Lu and Mustafa Akyol and Xi Chen and Hui Shi and Gang Han and Tong Shi and Guanghua Yu and Ahmet Ekicibil and Nick Kioussis and Ong, {P. V.} and Amiri, {Pedram Khalili} and Wang, {Kang L.}",

note = "Publisher Copyright: {\textcopyright} 2016 Elsevier B.V.",

year = "2017",

doi = "10.1016/j.jallcom.2016.09.309",

language = "English (US)",

volume = "694",

pages = "76--81",

journal = "Journal of Alloys and Compounds",

issn = "0925-8388",

publisher = "Elsevier B.V.",

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TY - JOUR

T1 - The impact of Hf layer thickness on the perpendicular magnetic anisotropy in Hf/CoFeB/MgO/Ta films

AU - Li, Minghua

AU - Lu, Jinhui

AU - Akyol, Mustafa

AU - Chen, Xi

AU - Shi, Hui

AU - Han, Gang

AU - Shi, Tong

AU - Yu, Guanghua

AU - Ekicibil, Ahmet

AU - Kioussis, Nick

AU - Ong, P. V.

AU - Amiri, Pedram Khalili

AU - Wang, Kang L.

PY - 2017

Y1 - 2017

N2 - The impact of Hf layer thickness on magnetic anisotropy is evaluated for Hf/CoFeB/MgO/Ta multilayer films commonly used in magnetic tunnel junctions (MTJs). An easy-axis magnetization transition from the in-plane to the out-of-plane direction is observed when the thickness of Hf is greater than ∼1.5 nm in our structure. Moreover, a critical Hf layer thickness exists for strong perpendicular magnetic anisotropy on the CoFeB/MgO interface that maintains the properties required for use in MTJs. We also perform X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD) to study the effects of film composition, chemical states, and crystallization on the magnetic anisotropy in Hf/FeCoB/MgO/Ta multilayers with Hf layers of various thicknesses.

AB - The impact of Hf layer thickness on magnetic anisotropy is evaluated for Hf/CoFeB/MgO/Ta multilayer films commonly used in magnetic tunnel junctions (MTJs). An easy-axis magnetization transition from the in-plane to the out-of-plane direction is observed when the thickness of Hf is greater than ∼1.5 nm in our structure. Moreover, a critical Hf layer thickness exists for strong perpendicular magnetic anisotropy on the CoFeB/MgO interface that maintains the properties required for use in MTJs. We also perform X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD) to study the effects of film composition, chemical states, and crystallization on the magnetic anisotropy in Hf/FeCoB/MgO/Ta multilayers with Hf layers of various thicknesses.

KW - CoFeB

KW - Hf

KW - Perpendicular magnetic anisotropy

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U2 - 10.1016/j.jallcom.2016.09.309

DO - 10.1016/j.jallcom.2016.09.309

M3 - Article

AN - SCOPUS:84989943655

SN - 0925-8388

VL - 694

SP - 76

EP - 81

JO - Journal of Alloys and Compounds

JF - Journal of Alloys and Compounds

ER -

The impact of Hf layer thickness on the perpendicular magnetic anisotropy in Hf/CoFeB/MgO/Ta films

Abstract

Keywords

ASJC Scopus subject areas

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