Pressure effects on the superconductivity of HfPd2Al Heusler compound: Experimental and theoretical study
| Autor: | Wiendlocha, B., Winiarski, M. J., Muras, M., Zvoriste-Walters, C., Griveau, J. -C., Heathman, S., Gazda, M., Klimczuk, T. |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | Phys. Rev. B 91, 024509 (2015) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.91.024509 |
| Popis: | 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 {\alpha} = 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 {\lambda_{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 {\lambda_{ep}} and its evolution with pressure. Theoretical results explain the experimentally observed decrease in Tc due to considerable lattice stiffening. Comment: 10 figures |
| Databáze: | arXiv |
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