Superconductivity up to 35 K in the Iron Platinum Arsenides (CaFe_1−xPt_xAs)₁₀Pt_4−yAs₈ with Layered Structures

Abstract

The family of iron arsenide superconductors is expanded by the new iron platinum compounds (CaFe1−xPtxAs10)Pt4−yAs8 with novel crystal structures. Layers of FeAs4/4 tetrahedra and of nearly planar PtAs4/2 squares with (As2)4− dumbbells are stacked in different ways, resulting in polytypes with triclinic or tetragonal symmetry. Superconductivity up to 35 K is induced either by Pt doping of the Fe site or by electron transfer from PtAs to FeAs layers.

Large magnetic penetration depth and thermal fluctuations in a superconducting Ca10(Pt3As8)[(FeKim1, Ronning2, Haberkorn3 et al. 2012Phys. Rev. B252260View full textAdd to dashboardCite

“…[8][9][10] The 10-3-8 phase has triclinic symmetry and a T c of up to 11 K upon Pt doping; the 10-4-8 phase has tetragonal symmetry with the highest T c of 38 K. It is worth noting that well-defined Fermi surface sheets with tetragonal symmetry, similar to other pnictides, are observed in the 10-3-8 phase in spite of its triclinic symmetry. 11 Anisotropy of the critical field in the 10-3-8 phase near T c , γ Hc2 (T c ) ≡ H ab c2 /H c c2 ≈ 10 ( Ref.…”

Superconductivity in Ca1-xLaxFeAs2: A Novel 112-Type Iron Pnictide with Arsenic Zigzag Bonds

“…[15][16][17][18] Because of the 4p 3 electron configuration of elemental arsenic, arsenic can form various bonding structures: (i) Isolated arsenic with a formal electron count of As 3À . Examples include A 3 As (A ¼ Li, Na, and K) and iron-based superconductors.…”

Superconductivity by transition metal doping in Ca10(Fe1−xMxAs)10(Pt3As8) (M= Co, Ni, Cu)

“…Polycrystalline samples of Co-, Ni-, and Cu-doped calcium platinum iron-arsenides were synthesized from the elements as described in [15], and characterized by Xray powder diffraction using the Rietveld method with TOPAS [25]. Compositions were determined within errors of 10% by X-ray spectroscopy (EDX).…”

“…The diffraction patterns are completely described with the 1038-phase structure model [15] and minor amounts of impurity phases FeAs and PtAs 2 . The high sample quality implies smooth incorporation of cobalt, nickel, and copper into the 1038 structure.…”

“…Relationships between the magneto-structural phase transition and superconductivity in iron arsenides have intensively been studied [5,[8][9][10][11][12][13][14]. In 2011 the new superconductors Ca 10 (Fe 1−x Pt x As) 10 (Pt 3 As 8 ) (1038 phase, space group P 1) and polymorphic Ca 10 (FeAs) 10 (Pt 4 As 8 ) (1048-phases, space groups P 4/n, P 2 1 /n, P 1) with critical temperatures up to 35 K were discovered [15][16][17]. This new class recently expanded by analogous compounds with iridium (Ir1048) [18] and palladium (Pd1038) [19] instead of platinum.…”