Semi-metals with properties in between metals and non-metals occur between these two elements ( As, Sb ).
Metalic character increases when moving down in group because the atomic size is increasing. When the atomic size increases, the outer shells are farther away. Metalic character relates to the ability to lose electron. Electron shielding causes the atomic radius to increase thus the outer electrons ionizes more readily than electrons in smaller atoms.
So Sb has more metalic character than As.
If we observe concept of periodic classification then Bi has more metalic character than Sb. It is last element of V group.