EFFECT OF HEAT-TREATMENT ON THE MAGNETIC AND STRUCTURAL-PROPERTIES OF PERPENDICULAR MAGNETIC-ANISOTROPY CONIREP FILMS PRODUCED BY ELECTROLESS DEPOSITION

The effect of heat-treatment on the magnetic and structural properties of electroless-plated CoNiReP films with various compositions were studied to determine their microstructure in the as-deposited conditions, as well as to estimate their thermal stability. Due to the difference in compositions, magnetic properties of the films were found to behave differently with heat-treatment. The films with high crystallinity showed larger changes in magnetic properties. The Co32Ni55Re6P7 film with the largest perpendicular magnetic anisotropy kept its positive anisotropy energy with treatment up to 500-degrees-C. The <002>-oriented hcp structure of this film was also maintained with treatment up to 500-degrees-C. However, heat-treatment at 600-degrees-C altered the crystal structure of the films from the <002> oriented hexagonal close-packed structure to face-centered cubic without preferred crystal orientation, causing a sharp change in the magnetic properties of the films. Since the formation of Ni3P compound and fcc regions was detected in the film with treatment higher than 500-degrees-C, it was assumed that in the as-deposited films the <002>-oriented hcp crystallites with high crystallinity segregate in the amorphous NiP phase.