Fig. 4: Theoretical phase diagram and overview of superconducting ferromagnets/magnetic superconductors.
From: Lithium intercalated FeSe as a high-temperature superconducting ferromagnet
a Calculated magnetic phase diagram of FeSe at various lithium dopings and effective Hubbard U. Pink/blue symbols indicate that the calculated ground state is antiferromagnetic (AFM)/ferromagnetic (FM). b Overview of material systems showing coexistence of superconductivity and ferromagnetism. Shaded bar indicates that \({T}_{m}\) of LixFeSe exceeds the highest temperature that we measure (225 K). Apart from LixFeSe of this work, other superconducting ferromagnets (\({T}_{m} > {T}_{{sc}}\)) include: cuprates (Ru-1222: Gd1.4Ce0.6RuSr2Cu2O10-δ9; Ru-1212: RuSr2GdCu2O810), U-based materials (UGe2 under high pressure4, URhGe5, UCoGe6), ZrZn250. Magnetic superconductors (\({T}_{m} < {T}_{{sc}}\)) include: HoMo6S851, HoNi2Bi2C52, ErRh4B453, RbEuFe4As42, CsEuFe4As42, EuFe2(As0.7P0.3)211, [(Li,Fe)OH]FeSe12,13. Among the listed materials, Ru-1222, Ru-1212 and [(Li,Fe)OH]FeSe host weak ferromagnetism arising from canted-AFM (c-AFM) and their corresponding \({{{\rm{T}}}}_{{{\rm{m}}}}\)-values represent the temperature for AFM ordering.
