Influence of Seed Layer Systems and Their Premagnetization by Low Temperature Annealing on Electrodeposited Ni-Fe Fluxgate Cores

Electrodeposited ferromagnetic nickel-iron is used as functional layers in several microsystems, e.g., in micro fluxgate magnetometers. The magnetic properties of the flux guiding magnetometer core structures characterize the sensor response. In this work, the influences of substrate, undercoating, and seed layer on the physical and magnetic properties of electrodeposited fluxgate cores are discussed. In addition, a magnetic annealing process with a temperature profile below Curie-temperature T_C is applied to the seed layer system, which accelerates the annealing time and reduces material stresses caused by high-temperature core treatment.