Magnetic induced uniaxial anisotropy in NiFe and NiFeCr films (abstract)

Abstract

We report the experimental results of magnetic uniaxial anisotropy induced during sputtering (K1) and annealing (K2) of NiFe and NiFeCr films. The NiFe and NiFeCr films of around 30 nm thickness were deposited using dc magnetron sputtering. Glass and Ta (20 nm) coated glass were used as substrates. The magnetic properties were determined using a B-H looper at 10 Hz. The crystal orientation was determined using x-ray diffraction. The results show that the predictions from a two-component anisotropy model (that is K2/[K1+K2]) for a 3 h 310 °C anneal are in good agreement with experimental data for both NiFe/glass and NiFeCr/glass, but not for NiFe/Ta/glass and NiFeCr/Ta/glass. This can be explained by the orientation effect from x-ray diffraction studies. The NiFe and NiFeCr have higher (111) preferred orientation when deposited on Ta coated glass as compared to samples deposited on glass only. The effects of annealing temperature and Ta underlayer will be discussed. The activation energy for magnetic annealing induced anisotropy will also be discussed.