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

✍ Scribed by W.H. Lee; H.H. Sung; K.J. Syu; J.Y. Chen

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 186 KB
• Volume: 470
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2009.11.101

✦ Synopsis

As revealed in the powder X-ray diffraction and crystallographic data, the parent compound LaPtSi, which crystallizes in the LaPtSi-type structure (I4 1 md), admits considerable vacancies up to 20% on the Pt sublattice while still retaining its tetragonal symmetry. The refined lattice parameters show that both the aaxis 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 T c with x is similar to the change in the reduced lattice parameters a and v. It is found that the T c change rate dT c /dx = À9.6 ± 0.6 K and dT c /dv = 1.5 ± 0.3 K/Å 3 .