Embodiments include inductors and methods of forming inductors. In an embodiment, an inductor may include a substrate core and a conductive through-hole through the substrate core. Embodiments may also include a magnetic sheath around the conductive through hole. In an embodiment, the magnetic sheath is separated from the plated through hole by a barrier layer. In an embodiment, the barrier layer is formed over an inner surface of the magnetic sheath and over first and second surfaces of the magnetic sheath.