High Curie temperature ferromagnetic structures of (Sb2Te3)1−x(MnSb2Te4)x with x = 0.7–0.8

Ido Levy (1) , Candice Forrester (1) , Xiaxin Ding (1) , Christophe Testelin (2, 3) , Lia Krusin-Elbaum (1) , Maria C Tamargo (1)

1 CCNY - City College of New York [CUNY]
2 INSP-E12 - Photonique et cohérence de spin
3 INSP - Institut des Nanosciences de Paris

Abstract Magnetic topological materials are promising for realizing novel quantum physical phenomena. Among these, bulk Mn-rich MnSb 2 Te 4 is ferromagnetic due to Mn Sb antisites and has relatively high Curie temperatures (T C ), which is attractive for technological applications. We have previously reported the growth of materials with the formula (Sb 2 Te 3 ) 1−x (MnSb 2 Te 4 ) x , where x varies between 0 and 1. Here we report on their magnetic and transport properties. We show that the samples are divided into three groups based on the value of x (or the percent septuple layers within the crystals) and their corresponding T C values. Samples that contain x < 0.7 or x > 0.9 have a single T C value of 15–20 K and 20–30 K, respectively, while samples with 0.7 < x < 0.8 exhibit two T C values, one (T C1 ) at ~ 25 K and the second (T C2 ) reaching values above 80 K, almost twice as high as any reported value to date for these types of materials. Structural analysis shows that samples with 0.7 < x < 0.8 have large regions of only SLs, while other regions have isolated QLs embedded within the SL lattice. We propose that the SL regions give rise to a T C1 of ~ 20 to 30 K, and regions with isolated QLs are responsible for the higher T C2 values. Our results have important implications for the design of magnetic topological materials having enhanced properties.

Mots clés: Topological insulator; Ferromagnetism; Anomalous Hall Effect; MnSb2Te4; MBE epitaxy

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Ido Levy, Candice Forrester, Xiaxin Ding, Christophe Testelin, Lia Krusin-Elbaum, et al.. High Curie temperature ferromagnetic structures of (Sb2Te3)1−x(MnSb2Te4)x with x = 0.7–0.8. Scientific Reports, 2023, 13 (1), pp.7381. ⟨10.1038/s41598-023-34585-y⟩. ⟨hal-04092162⟩