Effect of substrate temperature on NiO/Ni81Fe19 exchange coupling double-layered films

NiO films, NiFe films and double- layered NiO/NiFe films were prepared on glass substrates by rf magnetron sputtering. The temperature of substrates (TS) were varied from room temperature (TR) to 300℃. The HC of NiFe films deposited at TR was 584A·m-1, it became 184A·m-1 while the Ts increased to 260℃ and the squareness of hysteresis loop became better.The HC and HEX of NiO (50 nm)/ NiFe (15 nm) deposited at TR were 4000A·m-1 and 1600A·m-1,respectively. The HC decreased to 3120A·m-1 and HEX increased to 4640A·m-1 while the TS was 260℃. The squareness of hysteresis loop also became better and the blocking temperature (TB)was 230℃. XRD analysis indicated that the NiO films deposited at TR presented (220) texture whereas the films deposited at 260℃ showed (111) texture. The NiFe films deposited at TR and 260℃ both presented (111) texture, but the crystal particle size of the latter waJs larger.