Physical properties of single crystalline SrSn$_{4}$ and BaSn$_{5}$ superconductors*

We present the growths and detailed thermodynamic and transport measurements on single crystals of the recently discovered binary intermetallic superconductors, SrSn$_{4}$ and BaSn$_{5}$. Their superconducting transition temperatures T$_{c}$ are found to be 4.8 K and 4.4 K respectively. Both materials are strongly-coupled, possibly multi-band superconductors. Hydrostatic pressure causes a decrease in the superconducting transition temperature at the rate of $\approx \quad -$0.068 K/kbar for SrSn$_{4}$, and $\approx \quad -$0.053 K/kbar for BaSn$_{5}$. Band structure and upper superconducting critical field anisotropy of SrSn$_{4}$ suggest complex, multi-sheet Fermi surface formed by four bands. De Hass-van Alphen oscillations are observed in BaSn$_{5}$, which indicates a more complex topology of Fermi surface.