Specific Heat Study of the Non-centrosymmetric Superconductor LaPt3Si in Magnetic Fields

• Published in: Journal of physics. Conference series 2012-12, Vol.400 (2)
• Main Authors: Motoyama, G, Shiotsuki, M, Oda, Y, Yamaguchi, A, Sumiyama, A, Takeuchi, T, Settai, R, Ōnuki, Y
• Format: Article
• Language: English
• Subjects: Crystal structure; Crystallinity; Crystallography; Crystals; Exponential equations; Heat; Low temperature; Magnetic fields; Physics; Polycrystals; Single crystals; Specific heat; Superconductivity; Superconductors
• ISSN: 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/400/2/022079

We have measured the specific heat of poly- and single-crystalline LaPt3Si samples in various magnetic fields. In zero magnetic field, we observed distinct superconducting transitions at Tc ∼ 0.64 K and 0.61 K for the poly- and single crystals, respectively. Temperature T dependences of the specific heat C of both samples around Tc resembled each other and could be well described by an exponential equation for a conventional superconductor at low temperatures. In a magnetic field, a characteristic peak of C/T appeared while the Tc was considerably suppressed. These trends were pronounced for the single crystal. The transition of the polycrystal became broad above 40 Oe and a characteristic tail appeared at temperatures above the peak of C/T. We suggest that the tail is induced by domains that have crystallographic disorders of the non-centrosymmetry and a higher critical magnetic field than that of the bulk. These domains became superconducting at temperatures above the peak of C/T and then formed the tail. Both the poly- and single-crystalline LaPt3Si samples have been found to show characteristics that are in-between those of type-I and type-II superconductors.