Growth and characterization of superconducting bulk crystal [(SnSe)1+δ]m(NbSe2) misfit layer compounds

• Published in: Journal of alloys and compounds 2024-03, Vol.978, Article 173486
• Main Authors: Shu, Ryufa, Nagao, Masanori, Yamamoto, Chiaya, Arimoto, Keisuke, Yamanaka, Junji, Maruyama, Yuki, Watauchi, Satoshi, Tanaka, Isao
• Format: Article
• Language: English
• Subjects: Flux Growth; Highly Orientated Crystals; Layered Superconductor; Misfit Compound
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2024.173486

[(SnSe)1+δ]m(NbSe2) (m = 1–6, 8, and 12) highly orientated crystals 1–2 mm in size and well-defined c-planes were successfully grown using CsCl/KCl flux, including the first growth of crystals with m = 12. The stacked layers along the c axis in the obtained crystals were directly observed by transmission electron microscopy as m alternating layers of SnSe and single layers of NbSe2. The superconducting transition temperature of the obtained [(SnSe)1+δ]m(NbSe2) crystals decreased with an increase in the number of SnSe layers per unit cell. As the superconducting anisotropy parameters increase, a significant increase is observed between m = 4 and 5. This indicates that the superconducting dimensionality becomes more two-dimensional with an increasing m. •We have successfully grown [(SnSe)1+δ]m(NbSe2) (m = 1–6, 8, and 12) highly orientated crystals.•The obtained [(SnSe)1+δ]m(NbSe2) highly orientated crystals exhibited the superconductivity.•A significant increase of the superconducting anisotropy was observed between m = 4 and 5.