Specific heat of novel ternary superconductors La3Ni4X4 (X = Si and Ge)

S. Kasahara, H. Fujii, T. Mochiku, H. Takeya, K. Hirata

Research output: Contribution to journalArticlepeer-review

Abstract

A new superconductivity in ternary intermetallics of La3Ni4X4, where X = Si and Ge, has been found. The superconducting critical temperatures, Tcs, of La3Ni4Si4 and La3Ni4Ge4 defined as the onset of diamagnetism are 1.0 and 0.70 K, respectively. These superconductors have U3Ni4Si4-type crystal structure, with a combination of BaAl4-(ThCr2Si2-) and AlB2-type alternating layers. In this work, we present studies on low temperature specific heat in these nickel compounds to shed light on the superconducting natures. The Sommerfeld coefficient, γn, for both compounds showed relatively high values; γn = 37.4 mJ/mol K2 and 36.9 mJ/mol K2 are derived for La3Ni4Si4 and La3Ni4Ge4, respectively. The Debye temperature ΘD in La3Ni4Si4 is estimated as 321 K, while that in La3Ni4Ge4 is given as 284 K. As well as the electron-phonon coupling constant, the electronic density of states at the Fermi level is estimated. It turned out that these materials have high density of states, which is in common to the analogous of La3Pd4Ge4. A new superconductivity in the compounds with U3Ni4Si4-type structure is discussed based on the thermodynamic properties.

Original languageEnglish
Pages (from-to)1231-1233
Number of pages3
JournalPhysica C: Superconductivity and its applications
Volume468
Issue number15-20
DOIs
Publication statusPublished - Sep 15 2008
Externally publishedYes

Keywords

  • LaNiX
  • Specific heat
  • ThCrSi derivative
  • UNiSi-type structure

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering

Fingerprint

Dive into the research topics of 'Specific heat of novel ternary superconductors La<sub>3</sub>Ni<sub>4</sub>X<sub>4</sub> (X = Si and Ge)'. Together they form a unique fingerprint.

Cite this