  Single crystal of YCoGa5 has been grown via Ga self-flux. In this paper, we
report the single crystal growth, crystallographic parameters, resistivity,
heat capacity, and band structure results of YCoGa5. YCoGa5 accommodates the
HoCoGa5 type structure (space group P4/mmm (No. 123), Z = 1, a = 4.2131(6) A, c
= 6.7929(13) A, which is isostructural to the extensively studied heavy fermion
superconductor system CeMIn5 (M = Co, Rh, Ir) and the unconventional
superconductor PuCoGa5 with Tc = 18.5 K. No superconductivity is observed down
to 1.75 K. Band structure calculation results show that its band at the Fermi
level is mainly composed of Co-3d and Ga-4p electrons states, which explains
its similarity of physical properties to YbCoGa5 and LuCoGa5.
