Layer-number-independent two-dimensional ferromagnetism in Cr
Te
Cr
Te
における層数に依存しない2次元強磁性
Wang, Y.*; 梶原 駿*; 松岡 秀樹*; Saika, B. K.*; 山神 光平*; 竹田 幸治
; 和達 大樹*; 石坂 香子*; 岩佐 義宏*; 中野 匡規*
Wang, Y.*; Kajihara, Shun*; Matsuoka, Hideki*; Saika, B. K.*; Yamagami, Kohei*; Takeda, Yukiharu; Wadachi, Hiroki*; Ishizaka, Kyoko*; Iwasa, Yoshihiro*; Nakano, Masaki*
In a conventional magnetic material, a long-range magnetic order develops in three dimensions, and reducing a layer number weakens its magnetism. Here we demonstrate anomalous layer-number-independent ferromagnetism down to the two-dimensional (2D) limit in a metastable phase of Cr
Te
. We fabricated Cr
Te
thin films by molecular-beam epitaxy and found that Cr
Te
could host two distinct ferromagnetic phases characterized with different Curie temperatures (
). One is the bulk-like high-
phase showing room-temperature ferromagnetism, which is consistent with previous studies. The other is the metastable low-
phase with
160 K, which exhibits a layer-number-independent
down to the 2D limit in marked contrast with the conventional high-
phase, demonstrating a purely 2D nature of its ferromagnetism. Such significant differences between two distinct phases could be attributed to a small variation in the doping level, making this material attractive for future ultracompact spintronics applications with potential gate-tunable room-temperature 2D ferromagnetism.