Pressure effects on the superconductivity of HfPd2Al Heusler compound: Experimental and theoretical study

Abstract

Polycrystalline HfPd2Al has been synthesized using the arc-melting method and studied under ambient pressure conditions by x-ray diffraction from room temperature up to 450^oC. High pressure x-ray diffraction up to 23 GPa was also performed using Diacell-type membrane diamond anvil cells. The estimated linear thermal expansion coefficient was found to be α = 1.40(3)x10^{-5} K^{-1}, and the bulk modulus derived from the fit to the 3rd order Birch-Murnaghan EOS (BMEOS) is B0 = 97(2) GPa. Resistivity studies under applied pressure (p < 7.49 GPa) showed a linear decrease of superconducting critical temperature with increasing pressure and the slope dTc/dp = -0.13(1) K GPa^{-1}. The same behavior is observed for the electron-phonon coupling constant {λ_{ep}}(p) that changes from 0.67 to 0.6, estimated for p = 0.05 GPa and 7.49 GPa, respectively. First principles electronic structure and phonon calculation results are presented and used to estimate the magnitude of electron-phonon interaction {λ_{ep}} and its evolution with pressure. Theoretical results explain the experimentally observed decrease in Tc due to considerable lattice stiffening.

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References in corpus (10)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Electronic structure and magnetism of Fe${}_{3-x}$V${}_x$X (X = Si, Ga and Al) alloys by the KKR-CPA method
• Superconductivity in the Heusler Family of Intermetallics
• Importance of relativistic effects in electronic structure and thermopower calculations for Mg2Si, Mg2Ge and Mg2Sn
• Physical properties of the non-centrosymmetric superconductor Nb0.18Re0.82
• Theoretical search for superconductivity in Sc3XB perovskites and weak ferromagnetism in Sc3X (X = Tl, In, Ga, Al)
• Superconductivity of Mo3Sb7 from first principles
• High pressure effect on superconductivity of YB6
• Competition of ferromagnetism and superconductivity in Sc3InB
• Effect of the tetragonal distortion on the electronic structure, phonons and superconductivity in the Mo3Sb7 superconductor

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