The role of the (111) texture on the exchange bias and interlayer coupling effects observed in sputtered NiFe/IrMn/Co trilayers

Abstract

Magnetic properties of sputtered NiFe/IrMn/Co trilayers grown on different seed layers (Cu or Ta) deposited on Si (100) substrates were investigated by magnetometry and ferromagnetic resonance measurements. Exchange bias effect and magnetic spring behavior have been studied by changing the IrMn thickness. As shown by X-ray diffraction, Ta and Cu seed layers provoke different degrees of (111) fcc-texture that directly affect the exchange bias and indirectly modify the exchange spring coupling behavior. Increasing the IrMn thickness, it was observed that the coupling angle between the Co and NiFe ferromagnetic layers increases for the Cu seed system, but it reduces for the Ta case. The results were explained considering (i) different anisotropies of the Co and IrMn layers induced by the different degree of the (111) texture and (ii) the distinct exchange bias set at the NiFe/IrMn and IrMn/Co interfaces in both systems. The NiFe and Co interlayer coupling angle is strongly correlated with both exchange bias and exchange magnetic spring phenomena. It was also shown that the highest exchange bias field occurs when an unstressed L12 IrMn structure is stabilized.

Exchange bias in FeNi/FeMn/FeNi multilayers

“…Moreover, indirect interlayer coupling between FM layers across AF metallic layer like RKKY and orange-peel interactions between FM layers separated by a non-magnetic layer vanishes at the AF spacer thickness of the order of few nanometers [24][25][26][27]. Therefore, the suggestion about the existence of magnetic coupling between the FM layers through the AF layer is quite rare [28,29].…”

Effects of Nb buffer layer on superconducting and magnetic behavior of IrMn/NiFe/Nb/NiFe spin-valves

“…After that, when the sample is saturated in negative fields the alignment is P again [6,9]. In order to estimate some magnetic parameters from the curves, the derivatives of the descending and ascending branches of the loop were calculated [18][19][20] investigated NiFe/IrMn/Co trilayers grown on Ta or Cu seed layers and found that crystalline texture influences the trilayers' magnetic properties [22]. This way, as discussed above, the difference of the H C and H EB values for S Nb when compared to those for S Ta , obtained at 6 K, may be attributed to the degree of (200) preferred orientation of the IrMn layer in S Nb .…”

Origin and properties of an unexpected exchange bias of Ta/Ni80Fe20/Ir20Mn80/Ta heterostructure in ultrathin limit: Impact of the oblique deposition and Ta/Ni80Fe20 alloying

“…In previous work [20], it has been shown that the Cu (Ta) buffer layer induced a low (high) degree of [111] fiber-texture in the Si(100)/ Cu or Ta(10 nm)/Ni 80 Fe 20 (20 nm)/Ir 20 Mn 80 (4-15 nm)/Co(10 nm)/Ta or Cu(10 nm) deposited by oblique incidence in a confocal magnetron sputtering with the sample holder spinning at 0.5 Hz. The samples with high degree of [111] texture (with Ta buffer) presented a strong planar magnetic anisotropy, opposite to what happened to the samples with Cu.…”