Competing magnetic states in silicene and germanene 2D ferromagnets  

作　　者：Dmitry V.Averyanov Ivan S.Sokolov Mikhail S.Platunov Fabrice Wilhelm Andrei Rogalev Pierluigi Gargiani Manuel Valvidares Nicolas Jaouen Oleg E.Parfenov Alexander N.Taldenkov Igor A.Karateev Andrey M.Tokmachev Vyacheslav G.Storchak 

机构地区：[1]National Research Center“Kurchatov Institute”,Kurchatov Sq.1,Moscow,123182,Russia [2]ESRF-The European Synchrotron,CS 40220,38043,Grenoble Cedex 9,France [3]ALBA Synchrotron Light Source,Cerdanyola del Vallès,08290,Barcelona,Spain [4]L’Orme des Merisiers,Synchrotron SOLEIL,Gyf-sur-Yvette,91192,France

出　　处：《Nano Research》2020年第12期3396-3402,共7页纳米研究（英文版）

基　　金：This work was supported by National Research Center(NRC)“Kurchatov Institute”(No.1359,characterization);the Russian Science Foundation(No.19-19-00009(synthesis)and No.20-79-10028(magnetization measurements))。

摘　　要：Two-dimension(2D)magnets have recently developed into a class of stoichiometric materials with prospective applications in ultra-compact spintronics and quantum computing.Their functionality is particularly rich when different magnetic orders are competing in the same material.Metalloxenes REX2(RE=Eu,Gd;X=Si,Ge),silicene or germanene—heavy counterparts of graphene—coupled with a layer of rare-earth metals,evolve from three-dimension(3D)antiferromagnets in multilayer structures to 2D ferromagnets in a few monolayers.This evolution,however,does not lead to fully saturated 2D ferromagnetism,pointing at a possibility of coexisting/competing magnetic states.Here,REX2 magnetism is explored with element-selective X-ray magnetic circular dichroism(XMCD).The measurements are carried out for GdSi2,EuSi2,GdGe2,and EuGe2 of different thicknesses down to 1 monolayer employing K absorption edges of Si and Ge as well as M and L edges of the rare-earths.They access the magnetic state in REX2 and determine the seat of magnetism,orbital,and spin contributions to the magnetic moment.High-field measurements probe remnants of the bulk antiferromagnetism in 2D REX2.The results provide a new platform for studies of complex magnetic structures in 2D materials.

关 键 词：SILICENE germanene 2D ferromagnetism X-ray magnetic circular dichroism(XMCD) MONOLAYER 

分 类 号：O61[理学—无机化学]