Intrinsic valley polarization in 2D magnetic MXenes: surface engineering induced spin-valley coupling

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F21%3A10438743" target="_blank" >RIV/00216208:11310/21:10438743 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=jBSi61j8BT" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=jBSi61j8BT</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/d1tc02837e" target="_blank" >10.1039/d1tc02837e</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Intrinsic valley polarization in 2D magnetic MXenes: surface engineering induced spin-valley coupling

Popis výsledku v původním jazyce

Generating valley polarization for valleytronics applications requires breaking the inversion symmetry of two-dimensional (2D) hexagonal crystals. As such, 2D MXenes naturally lose their inversion symmetry upon surface functionalization, thereby opening up new design opportunities for controlling their physical and chemical properties. However, no spin-valley couplings have been proposed for magnetic MXenes thus far. Herein, we demonstrate that surface engineering not only breaks the inversion symmetry of 2D MXenes but also induces valley polarizations with diverse magnetic orders, including ferromagnetism, ferrimagnetism and antiferromagnetism. Using Cr2C-based MXenes as prototypes, our theoretical calculations showed that Janus MXenes Cr2COX (X = F, Cl and OH) are excellent candidates for ferrovalley materials, especially Cr2COF, which has a strong valley polarization of 334 meV and a high Curie temperature of 1146 K. Concurrently, Cr2C-based MXenes with mixed functionalizations (Cr2CO0.75F1.25 and Cr2CO1.25F0.75) displayed properties of ferrivalley and ferrovalley semiconductors, with 11 and 15 meV valley splitting, respectively. In other magnetic MXenes, surface engineering also induced valley properties, as shown by the new bipolar antiferrovalley identified in Cr2TiC2FCl MXene. Therefore, our study is the first proposal of an experimentally viable approach (i.e., surface engineering) for generating valley polarization in 2D MXenes by breaking their inversion symmetry while simultaneously providing a computational paradigm for probing other 2D nanomaterials with potential applications in valleytronics.

Název v anglickém jazyce

Intrinsic valley polarization in 2D magnetic MXenes: surface engineering induced spin-valley coupling

Popis výsledku anglicky

Generating valley polarization for valleytronics applications requires breaking the inversion symmetry of two-dimensional (2D) hexagonal crystals. As such, 2D MXenes naturally lose their inversion symmetry upon surface functionalization, thereby opening up new design opportunities for controlling their physical and chemical properties. However, no spin-valley couplings have been proposed for magnetic MXenes thus far. Herein, we demonstrate that surface engineering not only breaks the inversion symmetry of 2D MXenes but also induces valley polarizations with diverse magnetic orders, including ferromagnetism, ferrimagnetism and antiferromagnetism. Using Cr2C-based MXenes as prototypes, our theoretical calculations showed that Janus MXenes Cr2COX (X = F, Cl and OH) are excellent candidates for ferrovalley materials, especially Cr2COF, which has a strong valley polarization of 334 meV and a high Curie temperature of 1146 K. Concurrently, Cr2C-based MXenes with mixed functionalizations (Cr2CO0.75F1.25 and Cr2CO1.25F0.75) displayed properties of ferrivalley and ferrovalley semiconductors, with 11 and 15 meV valley splitting, respectively. In other magnetic MXenes, surface engineering also induced valley properties, as shown by the new bipolar antiferrovalley identified in Cr2TiC2FCl MXene. Therefore, our study is the first proposal of an experimentally viable approach (i.e., surface engineering) for generating valley polarization in 2D MXenes by breaking their inversion symmetry while simultaneously providing a computational paradigm for probing other 2D nanomaterials with potential applications in valleytronics.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

<a href="/cs/project/EF15_003%2F0000417" target="_blank" >EF15_003/0000417: Centrum pro cílenou syntézu a aplikace perspektivních materiálů</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Materials Chemistry C

ISSN

2050-7526

e-ISSN

—

Svazek periodika

9

Číslo periodika v rámci svazku

34

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

10

Strana od-do

11132-11141

Kód UT WoS článku

000678754000001

EID výsledku v databázi Scopus

2-s2.0-85114280338