There are also inductors made of nickel and silver coating, which is a more common ones in the form of an aluminum compound. 1r2 inductor is commonly made with nickel and silver coating.
2r2 coils are commonly used in manufacturing power inductors. Among them, a single coil is one of the most commonly used ones in manufacturing power inductors. The single coil is also called as nickel plating, and is a type of power coe that is not used in many applications.