Emergent Magnetic State in (111)-Oriented Quasi-Two-Dimensional Spinel Oxides

Xiaoran Liu; Sobhit Singh; Brian J. Kirby; Zhicheng Zhong; Yanwei Cao; Banabir Pal; Mikhail Kareev; Srimanta Middey; John W. Freeland; Padraic Shafer; Elke Arenholz; David Vanderbilt; Jak Chakhalian

doi:10.1021/acs.nanolett.9b02159

Emergent Magnetic State in (111)-Oriented Quasi-Two-Dimensional Spinel Oxides

Xiaoran Liu, Sobhit Singh, Brian J. Kirby, Zhicheng Zhong, Yanwei Cao, Banabir Pal, Mikhail Kareev, Srimanta Middey, John W. Freeland, Padraic Shafer, Elke Arenholz, David Vanderbilt, Jak Chakhalian

School of Arts and Sciences, New High Energy Theory Center

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

10 Scopus citations

Abstract

We report on the emergent magnetic state of (111)-oriented CoCr₂O₄ ultrathin films sandwiched between Al₂O₃ spacer layers in a quantum confined geometry. At the two-dimensional crossover, polarized neutron reflectometry reveals an anomalous enhancement of the total magnetization compared to the bulk value. Synchrotron X-ray magnetic circular dichroism measurements demonstrate the appearance of a long-range ferromagnetic ordering of spins on both Co and Cr sublattices. Brillouin function analyses and ab-initio density functional theory calculations further corroborate that the observed phenomena are due to the strongly altered magnetic frustration invoked by quantum confinement effects, manifested by the onset of a Yafet-Kittel-type ordering as the magnetic ground state in the ultrathin limit, which is unattainable in the bulk.

Original language	English (US)
Pages (from-to)	8381-8387
Number of pages	7
Journal	Nano Letters
Volume	19
Issue number	12
DOIs	https://doi.org/10.1021/acs.nanolett.9b02159
State	Published - Dec 11 2019

All Science Journal Classification (ASJC) codes

Bioengineering
General Chemistry
General Materials Science
Condensed Matter Physics
Mechanical Engineering

Keywords

Spinels
emergent properties
magnetism
ultrathin films

Access to Document

10.1021/acs.nanolett.9b02159

Cite this

@article{04ba4ae690bd454ea8190422ec5df9b2,

title = "Emergent Magnetic State in (111)-Oriented Quasi-Two-Dimensional Spinel Oxides",

abstract = "We report on the emergent magnetic state of (111)-oriented CoCr2O4 ultrathin films sandwiched between Al2O3 spacer layers in a quantum confined geometry. At the two-dimensional crossover, polarized neutron reflectometry reveals an anomalous enhancement of the total magnetization compared to the bulk value. Synchrotron X-ray magnetic circular dichroism measurements demonstrate the appearance of a long-range ferromagnetic ordering of spins on both Co and Cr sublattices. Brillouin function analyses and ab-initio density functional theory calculations further corroborate that the observed phenomena are due to the strongly altered magnetic frustration invoked by quantum confinement effects, manifested by the onset of a Yafet-Kittel-type ordering as the magnetic ground state in the ultrathin limit, which is unattainable in the bulk.",

keywords = "Spinels, emergent properties, magnetism, ultrathin films",

author = "Xiaoran Liu and Sobhit Singh and Kirby, {Brian J.} and Zhicheng Zhong and Yanwei Cao and Banabir Pal and Mikhail Kareev and Srimanta Middey and Freeland, {John W.} and Padraic Shafer and Elke Arenholz and David Vanderbilt and Jak Chakhalian",

note = "Publisher Copyright: {\textcopyright} 2019 American Chemical Society.",

year = "2019",

month = dec,

day = "11",

doi = "10.1021/acs.nanolett.9b02159",

language = "English (US)",

volume = "19",

pages = "8381--8387",

journal = "Nano Letters",

issn = "1530-6984",

publisher = "American Chemical Society",

number = "12",

}

TY - JOUR

T1 - Emergent Magnetic State in (111)-Oriented Quasi-Two-Dimensional Spinel Oxides

AU - Liu, Xiaoran

AU - Singh, Sobhit

AU - Kirby, Brian J.

AU - Zhong, Zhicheng

AU - Cao, Yanwei

AU - Pal, Banabir

AU - Kareev, Mikhail

AU - Middey, Srimanta

AU - Freeland, John W.

AU - Shafer, Padraic

AU - Arenholz, Elke

AU - Vanderbilt, David

AU - Chakhalian, Jak

PY - 2019/12/11

Y1 - 2019/12/11

N2 - We report on the emergent magnetic state of (111)-oriented CoCr2O4 ultrathin films sandwiched between Al2O3 spacer layers in a quantum confined geometry. At the two-dimensional crossover, polarized neutron reflectometry reveals an anomalous enhancement of the total magnetization compared to the bulk value. Synchrotron X-ray magnetic circular dichroism measurements demonstrate the appearance of a long-range ferromagnetic ordering of spins on both Co and Cr sublattices. Brillouin function analyses and ab-initio density functional theory calculations further corroborate that the observed phenomena are due to the strongly altered magnetic frustration invoked by quantum confinement effects, manifested by the onset of a Yafet-Kittel-type ordering as the magnetic ground state in the ultrathin limit, which is unattainable in the bulk.

AB - We report on the emergent magnetic state of (111)-oriented CoCr2O4 ultrathin films sandwiched between Al2O3 spacer layers in a quantum confined geometry. At the two-dimensional crossover, polarized neutron reflectometry reveals an anomalous enhancement of the total magnetization compared to the bulk value. Synchrotron X-ray magnetic circular dichroism measurements demonstrate the appearance of a long-range ferromagnetic ordering of spins on both Co and Cr sublattices. Brillouin function analyses and ab-initio density functional theory calculations further corroborate that the observed phenomena are due to the strongly altered magnetic frustration invoked by quantum confinement effects, manifested by the onset of a Yafet-Kittel-type ordering as the magnetic ground state in the ultrathin limit, which is unattainable in the bulk.

KW - Spinels

KW - emergent properties

KW - magnetism

KW - ultrathin films

UR - http://www.scopus.com/inward/record.url?scp=85074649787&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85074649787&partnerID=8YFLogxK

U2 - 10.1021/acs.nanolett.9b02159

DO - 10.1021/acs.nanolett.9b02159

M3 - Article

C2 - 31665887

AN - SCOPUS:85074649787

SN - 1530-6984

VL - 19

SP - 8381

EP - 8387

JO - Nano Letters

JF - Nano Letters

IS - 12

ER -

Emergent Magnetic State in (111)-Oriented Quasi-Two-Dimensional Spinel Oxides

Abstract

All Science Journal Classification (ASJC) codes

Keywords

Access to Document

Other files and links

Fingerprint

Cite this