Vacancy effects on Tc in superconducting LaPt1−xSi (0⩽x⩽0.2)

• Published in: Physica. C, Superconductivity Vol. 470; no. SUP1; pp. S774 - S775
• Main Authors: Lee, W.H., Sung, H.H., Syu, K.J., Chen, J.Y.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.2010; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Effects of material synthesis, crystal structure, and chemical composition; Exact sciences and technology; LaPt1−xSi; Physics; Superconductivity; Transition temperature variations; Vacancy effects; LaPt1−xSi; Vacancy effects; Superconductivity; Specific heat; Lanthanum Platinum Silicides Mixed; Vacancies; Superconducting transitions; Si; Sublattices; XRD; Lattice parameters; LaPt; Crystal structure
• ISSN: 0921-4534; 1873-2143
• DOI: 10.1016/j.physc.2009.11.101

As revealed in the powder X-ray diffraction and crystallographic data, the parent compound LaPtSi, which crystallizes in the LaPtSi-type structure (I41md), admits considerable vacancies up to 20% on the Pt sublattice while still retaining its tetragonal symmetry. The refined lattice parameters show that both the a-axis and the volume of the unit cell v contract clearly, though the c-axis exhibits less percentage change due to the existence of vacancies in the compound. These results are consonant with what one would expect from a chemical pressure effect. Magnetic and heat-capacity measurements demonstrate that the change in Tc with x is similar to the change in the reduced lattice parameters a and v. It is found that the Tc change rate dTc/dx=−9.6±0.6K and dTc/dv=1.5±0.3K/Å3.