Nodeless superconducting gaps in Ca$_{10}$(Pt$_{4-\delta}$As$_8$)((Fe$_{1-x}$Pt$_{x}$)$_2$As$_2$)$_5$ probed by quasiparticle heat transport

摘要: The in-plane thermal conductivity of iron-based superconductor Ca$_{10}$(Pt$_{4-\delta}$As$_8$)((Fe$_{1-x}$Pt$_{x}$)$_2$As$_2$)$_5$ single crystal (``10-4-8", $T_c$ = 22 K) was measured down to 80 mK. In zero field, the residual linear term $\kappa_0/T$ is negligible, suggesting nodeless superconducting gaps in this multiband compound. magnetic fields, increases rapidly, which mimics those NbSe$_2$ and LuNi$_2$B$_2$C with highly anisotropic gap. Such a field dependence an evidence for multiple quite different magnitudes or Comparing London penetration depth results Ca$_{10}$(Pt$_3$As$_8$)((Fe$_{1-x}$Pt$_{x}$)$_2$As$_2$)$_5$ (``10-3-8") compound, 10-4-8 10-3-8 compounds may have similar gap structure.