Specific Heat on the Non-centrosymmetric Superconductor LaPt3Si

We have measured specific heat of poly and single crystalline LaPt3Si samples under various magnetic fields. For zero magnetic field, we observed a distinct peak and jump in the specific heat at the super-conducting transition temperature T-c similar to 0.64 K and 0.61 K for the poly and single crystals, respectively. Temperature dependences of the specific heat of both samples below T-c can be well-described by a exponential equation for a conventional superconductor at zero magnetic field. The jump at T-c of single crystal is still distinct under magnetic fields. On the other hand, the peak of the poly crystal becomes broad above 40 Gauss. The broad additional specific heat tail appears at higher temperatures than the T-c expected from the results of the single crystal. We show, for the first time, the temperature dependence of superconducting critical magnetic field H-c(T) obtained from the specific heat measurement. Small anisotropy of H-c(T) was observed for the single crystal, with H-c,(0) = 66 and 61 Gauss for H//a and H//c, respectively.