Evolution of superconductivity and weak magnetism in inclination interfaces of Bi, Sb and Bi1-xSbx (0.07 ≤x ≤ 0.2) alloys. (September 2019)

• Record Type: Journal Article
• Authors: Muntyanu, F.M.; Nenkov, K.; Zaleski, A.J.; Muntean, N.; Chistol, V.
• Is Part Of: Solid state communications. Volume 299(2019)
• Publication Date: 2019-09
• Subjects: A. bismuth -- Antimony -- Bismuth-antimony alloys -- A. bicrystal interface -- D. superconductivity and ferromagnetism -- D. 3D topological insulator; Solid state chemistry -- Periodicals; Solid state physics -- Periodicals; Chimie de l'état solide -- Périodiques; Physique de l'état solide -- Périodiques; 530.41
• DOI: 10.1016/j.ssc.2019.113660
• Languages: English
• ISSNs: 0038-1098

Abstract

Abstract: Using Quantum Design SQUID magnetometer, we studied the magnetic and superconducting properties of high quality inclination bicrystal interfaces of Bi, Sb and 3D topological insulator Bi1-x Sbx (0.06 ≤ x ≤ 0.2). One or two superconducting phases with T c ≤ 21 K and magnetic hysteresis loops on a diamagnetic background typical for strong type II superconductors were identified in Bi and some Bi-Sb nano-width interfaces. However, the other interfaces of Bi1-x Sbx (0.06 ≤ x ≤ 0.2) as well as of Sb with a higher carrier density exhibit a superconducting transition and a ferromagnetic hysteresis loop or a dual loop (superimposed ferromagnetic and superconducting loops) against a paramagnetic background and thereby indicate the occurrence of superconductivity and weak ferromagnetism. Highlights: We study the nano-width inclination bicrystal interfaces of Bi, Sb, and 3D topological insulator Bi-Sb. The bicrystal interfaces of Bi present superconductivity, while those of Sb and Bi-Sb exhibit superconductivity and weak magnetism. The superconductivity of bicrystal interfaces results from the reconstruction of the rhombohedral crystal structure A7 under deformations. We have found that the interfaces of Sb and Bi-Sb bicrystals develop characteristics of 3D topological insulators.