Abstract

Isoelectronic Tellurium (Te) substitution for Selenium (Se) in the tetragonal phase of FeSe (β-FeSe) increases the superconducting transition temperature ( T c ) by applying a negative pressure on the lattice. However, the normal state resistivity increases and shows semi-metallic behavior for samples with higher Te concentration. With increasing Te concentration, the T c increases and reaches a maximum for FeSe 0.5Te 0.5 and then decreases with further increase of Te. We have investigated the effect of Cobalt (Co) and Nickel (Ni) doping in FeSe 0.5Te 0.5 in the nominal composition range Fe 1− x TM x Se 0.5Te 0.5 (TM = Co ( x = 0.05, 0.1, 0.15, 0.2) and Ni ( x = 0.05, 0.1)). Both Co and Ni doping suppress T c and drives the system to metal–insulator transition. The in-plane (‘ a’) and out-of-plane (‘ c’) lattice constants decrease with increasing dopant concentration.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.