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Electronic and Magnetic Properties of α-FeGe2 : = A Potential Material for 2D Spintronics.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Electronic and Magnetic Properties of α-FeGe2 :/
Reminder of title:	A Potential Material for 2D Spintronics.
Author:	Czubak, Dietmar.
Description:	1 online resource (143 pages)
Notes:	Source: Dissertations Abstracts International, Volume: 84-05, Section: B.
Contained By:	Dissertations Abstracts International84-05B.
Subject:	Crystal structure. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=29703292click for full text (PQDT)
ISBN:	9798352971833

Electronic and Magnetic Properties of α-FeGe2 : = A Potential Material for 2D Spintronics.
Czubak, Dietmar.

Electronic and Magnetic Properties of α-FeGe2 :A Potential Material for 2D Spintronics. - 1 online resource (143 pages)

Source: Dissertations Abstracts International, Volume: 84-05, Section: B.

Thesis (Ph.D.)--Humboldt Universitaet zu Berlin (Germany), 2022.

Includes bibliographical references

The rapid progress in the development of new 2D materials have also enriched spintronic research in recent years, thanks to their versatile physical properties and flexibility with regard to the design of heterostructures. The prominent examples graphene and transition metal dichalcogenides (TMDs) have the prospect to represent the basis of future spintronic applications, in particular due to their tunability and multifunctionality. The recently discovered metastable layered material α-FeGe2 is a potential candidate for being added to this class of materials. In this work, the electrical and magnetic properties of α-FeGe2 are studied, based on results from electrical transport measurements at different external magnetic fields and temperatures. For the investigation of magnetoresistive effects, spin valve devices containing α-FeGe2 as spacer layer between two metallic ferromagnets have been utilized. It is shown that α-FeGe2 exhibits a thickens dependent critical temperature around 100 K at which it undergoes a magnetic phase transition from an antiferromagnetic state at T > 100 K to a ferromagnetic state at T < 100 K. This phase transition is also predicted by density functional theory (DFT) calculations and reflected in a disappearing spin valve signal at low temperatures. It is demonstrated that the magnetic phase of the α-FeGe2 spacer strongly influences the performance of spin valves, particularly via the impact on the magnetic interlayer coupling between the ferromagnetic electrodes made of Fe3Si or Co2FeSi. The magnetic coupling at the interface between antiferromagnetic α-FeGe2 and Fe3Si was found to induce anisotropies in the spin valve signal with regard to the external magnetic field orientation. This anisotropy is explained in terms of a complex interplay between the misalignment between the ferromagnetic electrodes and the magnetically preferred direction of the antiferromagentic α-FeGe2 described by the Neel vector.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2023

Mode of access: World Wide Web

ISBN: 9798352971833Subjects--Topical Terms:

3561040
Crystal structure.
Index Terms--Genre/Form:

542853
Electronic books.

Electronic and Magnetic Properties of α-FeGe2 : = A Potential Material for 2D Spintronics.
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245 1 0 $a Electronic and Magnetic Properties of α-FeGe2 : $b A Potential Material for 2D Spintronics.
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300 $a 1 online resource (143 pages)
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500 $a Source: Dissertations Abstracts International, Volume: 84-05, Section: B.
500 $a Advisor: Engel-Herbert, Roman; Fischer, Saskia; Weiss, Dieter.
502 $a Thesis (Ph.D.)--Humboldt Universitaet zu Berlin (Germany), 2022.
504 $a Includes bibliographical references
520 $a The rapid progress in the development of new 2D materials have also enriched spintronic research in recent years, thanks to their versatile physical properties and flexibility with regard to the design of heterostructures. The prominent examples graphene and transition metal dichalcogenides (TMDs) have the prospect to represent the basis of future spintronic applications, in particular due to their tunability and multifunctionality. The recently discovered metastable layered material α-FeGe2 is a potential candidate for being added to this class of materials. In this work, the electrical and magnetic properties of α-FeGe2 are studied, based on results from electrical transport measurements at different external magnetic fields and temperatures. For the investigation of magnetoresistive effects, spin valve devices containing α-FeGe2 as spacer layer between two metallic ferromagnets have been utilized. It is shown that α-FeGe2 exhibits a thickens dependent critical temperature around 100 K at which it undergoes a magnetic phase transition from an antiferromagnetic state at T > 100 K to a ferromagnetic state at T < 100 K. This phase transition is also predicted by density functional theory (DFT) calculations and reflected in a disappearing spin valve signal at low temperatures. It is demonstrated that the magnetic phase of the α-FeGe2 spacer strongly influences the performance of spin valves, particularly via the impact on the magnetic interlayer coupling between the ferromagnetic electrodes made of Fe3Si or Co2FeSi. The magnetic coupling at the interface between antiferromagnetic α-FeGe2 and Fe3Si was found to induce anisotropies in the spin valve signal with regard to the external magnetic field orientation. This anisotropy is explained in terms of a complex interplay between the misalignment between the ferromagnetic electrodes and the magnetically preferred direction of the antiferromagentic α-FeGe2 described by the Neel vector.
520 $a Die rasanten Fortschritte bei der Entwicklung neuartiger 2D-Materialien haben in den letzten Jahren auch das Forschungsfeld der Spintronik stetig bereichert aufgrund der vielseitigen physikalischen Eigenschaften und der Flexibilitat hinsichtlich der Realisierung von Heterostrukturen. Das erst kurzlich entdeckte metastabile und geschichtete Material α-FeGe2 tragt das Potenzial, in die Klasse der bekannten 2DMaterialien aufgenommen zu werden. Materialien wie Graphen oder Ubergangsmetalldichalkogenid (TMDs) sind bereits aussichtsreiche Kandidaten fur zukunftige spintronische Anwendungen in Bezug auf Abstimmbarkeit und Multifunktionalitat. In dieser Dissertation werden die elektrischen und magnetischen Eigenschaften von α-FeGe2 diskutiert, basierend auf elektrischen Transportmessungen bei unterschiedlichen auseren Magnetfeldern und Temperaturen. Zur Untersuchung von magnetoresistiven Effekten wurden Spinventilstrukturen mit α-FeGe2 als Trennmaterial zwischen zwei metallische Ferromagnete verwendet. Es wird gezeigt, dass α-FeGe2 eine dickenabhangige kritische Temperatur besitzt, die bei etwa 100 K liegt und mit einem magnetischen Phasenubergang von der antiferromagnetischen Phase fur T > 100 K in die ferromagnetische Phase bei T < 100 K verknupft ist. Dieser Phasenubergang wird von Berechnungen aus der Dichtefunktionaltheorie (DFT) gestutzt und spiegelt sich auch in dem verschwindenden Spinventilsignal bei tiefen Temperaturen wieder. Es wird gezeigt, dass die magnetische Ordnung in der αFeGe2-Trennschicht einen starken Einfluss auf die Spinventilsignale ausubt. Insbesonders spielt hierbei die Auswirkung auf die magnetische Interschichtkopllung zwischen den ferromagnetischen Elektroden aus Fe3Si oder Co2FeSi eine entscheidende Rolle. Die magnetische Kopplung an der Grenzflache zwischen antiferromagnetischem α-FeGe2 und Fe3Si fuhrt zu einer Anisotropie in den Spinventilsignalen hinsichtlich der Orientierung des externen Magnetfeldes. Diese Anisotropie wird durch ein komplexes Zusammenspiel zwischen der Magnetisierung der ferromagnetischen Elektroden und der magnetischen Vorzugsrichtung des antiferromagnetischen α-FeGe2, die durch den sog. Neelvektor beschrieben wird, diskutiert.
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538 $a Mode of access: World Wide Web
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710 2 $a Humboldt Universitaet zu Berlin (Germany). $3 3480542
773 0 $t Dissertations Abstracts International $g 84-05B.
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