Atmospheric plasma sprayed cobalt ferrite coatings for magnetostrictive sensor applications

Cobalt ferrite powder was synthesized by chemical co-precipitation followed by a heat treatment at 1100°C for 10 h, and was subsequently deposited onto titanium and alumina substrates using atmospheric plasma spraying technique. X-ray diffraction results indicate that the as-deposited coating consists of spinel and wustite phase. The hysteresis loop measurements show that the coating has a relatively low saturation magnetization and a coercivity of 1270 Oe for in-plane direction. Magnetostriction of the as-deposited coating at ambient temperature is -73 × 10^-6 with an applied magnetic field of 4530 Oe.