Carrier doping enhanced ferromagnetism in Fe5−xGeTe2

Low dimensional magnetic systems beyond the realm of Mermin–Wagner theorem is of particular interests [1]. Recently, Fe5−xGeTe2 as a layered two-dimensional (2D) van der Waals (vdW) magnetic metal with an above-room-temperature magnetic transition temperature Tc is discovered [2-3]. This compound is particularly interesting because of its large Tc, strong magnetization and Fe-content tunable moment direction. In addition, it has been reported that Co doping can efficiently tune the lattice structure and magnetic ground states [4-5]. Here, we report another system of carrier doping in Fe5−xGeTe2, which dramatically alter the magnetic properties. Our work reveals a new arena for studying the 2D vdW magnetic metals with strong room temperature ferromagnetism.

[1]  N. D. Mermin and H. Wagner,  Phys.  Rev.Lett.17, 1133 (1966).

[2] A.  F.  May,  D.  Ovchinnikov,  Q.  Zheng,  R.  Hermann,S. Calder, B. Huang, Z. Fei, Y. Liu, X. Xu, and M. A.McGuire,  ACSNano13, 4436 (2019).

[3] H.  Zhang,  R.  Chen,  K.  Zhai,  X.  Chen,  L.  Caretta,X.  Huang,  R.  V.  Chopdekar,  J.  Cao,  J.  Sun,  J.  Yao,R. Birgeneau, and R. Ramesh, Phys. Rev. B102, 064417 (2020)

[4] A. F. May, M.-H. Du, V. R. Cooper, and M. A. McGuire,  Phys.  Rev.  Materials4, 074008 (2020).

[5] H.  Zhang,  Y.-T.  Shao,  R.  Chen,  X.  Chen,  S.  Susarla,J.  T.  Reichanadter,  L.  Caretta,  X.  Huang,  N.  S.  Set-tineri, Z. Chen, J. Zhou, E. Bourret-Courchesne, P. Er-cius, J. Yao, J. B. Neaton, D. A. Muller, R. J. Birgeneau,and R. Ramesh,  arXiv:2106.00833 [cond-mat.mtrl-sci].