Strong-Coupling Superconductivity in BaPd2As2 Induced by Soft Phonons in the ThCr2Si2-type Polymorph

Abstract

The specific heat of two polymorphs of BaPd2As2 was measured. The ThCr2Si2-type polymorph (space group I4/mmm, $D_{4h}^{17}$, No. 139) is a previously reported superconductor with a transition temperature Tc $\simeq$ 3.5 K, while the CeMg2Si2-type polymorph (P4/mmm, $D_{4h}^1$, No. 123) is a normal metal and does not exhibit superconductivity down to 1.8 K. Our results revealed that the ThCr2Si2-type has an anomalously low Debye temperature, indicative of soft phonons, compared to the CeMg2Si2-type. Moreover, a large specific-heat jump at Tc indicated that the superconductivity of ThCr2Si2-type is a strong-coupling type, which is likely derived from soft phonons.

arXiv comment5 pages, 4 figures, 1 table

References in corpus (21)

• To What Extent Iron-Pnictide New Superconductors Have Been Clarified: A Progress Report
• Exploration of new superconductors and functional materials and fabrication of superconducting tapes and wires of iron pnictides
• Extremely strong-coupling superconductivity and anomalous lattice properties in the beta-pyrochlore oxide KOs2O6
• Superconductivity in SrNi2As2 Single Crystals
• Structure and Anisotropic Properties of BaFe2-xNixAs2 (x = 0, 1, 2) Single Crystals
• Rattling-Induced Superconductiviy in the Beta-Pyrochlore Oxides AOs2O6
• Density functional study of BaNi${}_2$As${}_2$: Electronic structure, phonons and electron-phonon superconductivity
• Superconductivity and the Effects of Pressure and Structure in Single Crystalline SrNi${}_2$P${}_2$
• Superconducting and Normal State Properties of APd2As2 (A = Ca, Sr, Ba) Single Crystals
• Giant Phonon Softening and Enhancement of Superconductivity by Phosphorus Doping of BaNi2As2
• The emergence of superconductivity in BaNi2(Ge1-xPx)2 at a structural instability
• Superconductivity in Layered Pnictides BaRh2P2 and BaIr2P2
• Strong Electron-Phonon Coupling Superconductivity Induced by a Low-lying Phonon in IrGe
• Superconductivity at 3.85 K in BaPd2As2 with the ThCr2Si2-type structure
• Strong-Coupling Theory of Rattling-Induced Superconductivity
• Superconductivity and structural distortion in BaPt${}_2$As${}_2$
• Superconductivity in the ternary iridium-arsenide BaIr2As2
• Superconductivity and multiple pressure-induced phases in BaPt${}_2$As${}_2$
• Comparative Study of Electronic structure of New Superconductors (Sr,Ca)Pd2As2 and related compound BaPd2As2
• Superconductivity in Pseudo-Binary Silicide SrNixSi2-x with AlB2-Type Structure
• Enhanced Superconductivity in Close Proximity to the Structural Phase Transition of Sr1-xBaxNi2P2

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