Characterization of the high-pressure superconductivity in the Pnma phase of calcium

R. Szczesniak, D. Szczesniak

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

The thermodynamic parameters of the superconducting state in calcium under the pressure of 161GPa have been calculated within the framework of the Eliashberg approach. It has been shown that the value of the Coulomb pseudopotential is high (μ* C=0.24) and the critical temperature (TC=25K) should be determined from the modified Allen-Dynes formula. In addition, it has been found that the basic dimensionless ratios of the thermodynamic parameters significantly diverge from the BCS predictions, and take the following values: (i) The zero-temperature energy gap to the critical temperature (R1≡ 2Δ(0)/kBTC) is equal to 4.01. (ii) The ratio R2≡ (CS(TC) equals 2.17, where CSand CNdenote the specific heats for the superconducting and normal states, respectively. (iii) The quantity R3≡TCCN(TC)/H2 C(0)=0.158, where HCindicates the thermodynamic critical field. Finally, it has been proven that the electron effective mass is large and takes the maximum of 2.32meat TC.

Original languageEnglish
Pages (from-to)2194-2201
Number of pages8
JournalPhysica Status Solidi (B) Basic Research
Volume249
Issue number11
DOIs
Publication statusPublished - 2012
Externally publishedYes

Fingerprint

Superconductivity
calcium
Calcium
superconductivity
Thermodynamics
thermodynamics
critical temperature
Temperature
pseudopotentials
Specific heat
Energy gap
specific heat
Electrons
predictions
electrons
temperature

Keywords

  • Ca Pnma phase
  • High-pressure effects
  • Superconductivity
  • Thermodynamic properties

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Cite this

Characterization of the high-pressure superconductivity in the Pnma phase of calcium. / Szczesniak, R.; Szczesniak, D.

In: Physica Status Solidi (B) Basic Research, Vol. 249, No. 11, 2012, p. 2194-2201.

Research output: Contribution to journalArticle

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