  Potassium intercalated FeSe has been reported as a superconductor with
superconducting transition temperatures ($T_{\rm c}$'s) of 30-48 K. However,
there is no clear answer to identify the relationship between the surface
morphology, compositional ratio and its crystal structure. This report directly
reveals the correspondence among these three characteristics in single crystals
with a $T_{\rm c}$ onset of around 44 K using a micro-sampling technique.
Island-like parts on the surface of the crystals clearly have the
K$_x$Fe$_2$Se$_2$ structure with perfect FeSe layers, which is formed in
conjunction with the K$_2$Fe$_4$Se$_5$ phase. This results in the appearance of
the $T_{\rm c}$ onset of 44 K.
