Possible multigap superconductivity and magnetism in single crystals of superconducting La2Pt3Ge5and Pr

Abstract

We herein describe our investigation of the superconducting and magnetic properties of the rare-earth ternary germanide intermetallic compounds La 2 Pt 3 Ge 5 and Pr 2 Pt 3 Ge 5 . Single crystals of La 2 Pt 3 Ge 5 and Pr 2 Pt 3 Ge 5 were synthesized using the high temperature metal flux method.Both types of crystal formed in a U 2 Co 3 Si 5 -type orthorhombic structure (space group Ibam). La 2 Pt 3 Ge 5 showed the onset of superconducting phase transition at T c = 8.1 K, which, to the best of our knowledge, is the highest T c of all the RE 2 T M 3 X 5 (RE = Rare Earth elements, T M = Transition metal, and X = s − p metal) superconductors, and from the specific heat data, it was found to have multi-gap superconductivity. Pr 2 Pt 3 Ge 5 showed both a superconducting phase transition at T c = 7.8 K and two antiferromagnetic transitions at T N 1 = 3.5 K and T N 2 = 4.2 K, which indicates the coexistence of superconductivity and magnetism. However, the correlation between the superconductivity and the magnetism was too weak to be observed. In its normal state, Pr 2 Pt 3 Ge 5 revealed strong magnetic anisotropy, probably due to the crystalline electric field effect.

Normal-state charge dynamics of ternary platinum germanide superconductor La2Pt3Ge5

“…Among the rare-earth ternary intermetallic superconductors, a platinum germanide La 2 Pt 3 Ge 5 has the highest T c of 8.1 K [6]. The specific heat data of La 2 Pt 3 Ge 5 showed unusual behavior below T c , which is similar to the case of Lu 2 Fe 3 Si 5 [6].…”

“…The specific heat data of La 2 Pt 3 Ge 5 showed unusual behavior below T c , which is similar to the case of Lu 2 Fe 3 Si 5 [6]. The specific heat jump at T c was found to be about 0.36, which is much smaller than the BCS value.…”

“…The as-grown crystals have large and flat bc plane. Details of the growth procedure are described elsewhere [6]. We measured the bc-plane reflectance R() spectra of La 2 Pt 3 Ge 5 in the energy region between 50 and 8000 cm -1 by using Fourier-transform infrared spectrometer (Bruker Vertex 70v).…”

Nd8Co4−Al Ge2C3: A case study in flux growth of lanthanide-rich intermetallics

“…More complex structures can also be obtained from mixed fluxes; reactions of Pr in excess Pt/Ge mixture produces large crystals of superconducting Pr 2 Pt 3 Ge 5 up to 10 mm in length [18]. reported crystal growth of late lanthanide Ln 2 Cu 2 In compounds using the self-flux method; this was referred to as a Ln/Cu/In ternary melt, but the amount of indium used was small (reaction mixtures were (Gd 0.5 Cu 0.5 ) 1-x In x with 0.05<x<0.15), so it can be viewed as growth from a Ln/Cu flux [24].…”

Magnetic and Electronic Properties of the Ternary Compound U2T3Si5 (T = Rh, Ir)

“…There are three crystal structure types reported in these systems, which are the Lu2Co3Si5-type monoclinic (space group: C2/c), U2Co3Si5-type orthorhombic (space group: Ibam) structures, and Lu2Fe3Si5-type tetragonal (space group: P4/mnc). Several interesting physical properties in this system are reported such as the pressure-induced heavy fermion superconductivity in Ce2Ni3Ge5 [5], and the coexistence of antiferromagnetism and superconductivity in Pr2Pt3Ge5 [6], etc.…”