Evolution of the Phase Diagram of LaFeP$_{1-x}$As$_{x}$O$_{1-y}$F$_{y}$ ($y$ = 0 -- 0.1)

• Main Authors: Lai, K. T, Takemori, A, Miyasaka, S, Engetsu, F, Mukuda, H, Tajima, S
• Format: Journal Article
• Language: English
• Published: 04.08.2014
• Subjects: Physics - Superconductivity
• DOI: 10.48550/arxiv.1408.0584

Phys. Rev. B 90, 064504 (2014) P/As-substitution effects on the transport properties of polycrystalline LaFeP$_{1-x}$As$_{x}$O$_{1-y}$F$_{y}$ with $x$ = 0 -- 1.0 and $y$ = 0 -- 0.1 have been studied. In the F-free samples ($y$ = 0), a new superconducting (SC) dome with a maximum $T_{c}$ of 12 K is observed around $x$ = 0 -- 0.3. This is separated from another SC dome with $T_{c}$ $\sim$10 K at $x$ = 0.6 -- 0.8 by an antiferromagnetic region ($x$ = 0.3 -- 0.6), giving a two-dome feature in the $T_{c}-x$ phase diagram. As $y$ increases, the two SC domes merge together, changing to a double peak structure at $y$ = 0.05 and a single dome at $y$ = 0.1. This proves the presence of two different Fermi surface states in this system.