An example device includes a mounting structure including a first material having a first coefficient of thermal expansion (CTE). The mounting structure includes a center portion and an outer portion. The device further includes a magnetic core for an electrical component that is coupled to the outer portion of the mounting structure. The magnetic core includes a second material having a second CTE. The magnetic core is split into a plurality of sections separated by spaces extending from the center portion to an outer edge of the outer portion. Each of the plurality of sections is separately coupled to the mounting structure, and each of the plurality of sections is connected to the electrical component.