Room temperature superparamagnetism in ternary (Fe50Pt50)0.42Cu0.58 phase at interfaces on annealing of Fe50Pt50/Cu multilayer

Annealing driven positive and negative exchange bias in Fe–Cu–Pt heterostructures at room temperature

“…These ternary alloys show drastically different magnetic properties [27][28][29][30][31][32]. Earlier, we studied the formation of ternary alloy FePtCu on annealing FePt/Cu multilayer, where Cu thickness was larger than the FePt alloy and it resulted in formation of (FePt) 0.42 Cu 0.58 [26]. The ternary alloy of FCT phase was obtained on annealing the multilayer at 400 o C, due to high diffusivity of the elements in this system, which exhibited a superparamagnetic behavior.…”

“…Recently, efforts have been made to reduce the ordering temperature by introducing (a) a buffer layer [16][17][18][19][20], (b) a cap layer [21,22], and (c) addition of third element to form a ternary alloy compound [23][24][25][26]. One of the effective ways to reduce the ordering (FCC to FCT) temperature of FePt film is by adding Cu to FePt and realizing the formation of (FePt) 1-x Cu x ternary alloys (x = 0-30%) [27][28][29][30][31][32].…”