Tailoring the exchange bias of Ni/NiO nanogranular samples by the structure control

Exchange bias and training effect in Ni/Ag-doped NiO bilayers

“…7(a)) exhibits two features: (i) an intermediate temperature region (260 KZTZ100 K), where -H e increases slightly with decrease in T; (ii) a low temperature fast increase (Tr100 K). The low temperature fast increase of À H e is also found for CoO/Co bilayers [23] and NiO/Ni granular systems [24,25], which is attributed to the low freezing temperature spins at the interface, which are weakly coupled to the spins in the core of the AF grains [23], or the spin glass phase at the interface due to the structural disorder and frustration of competing magnetic interaction [25,26]. For the x=0.2 sample, À H e is lower in the temperature region of 300 4T450 K; when T drops below 50 K, ÀH e is slightly larger than that of the x=0 sample.…”

Magnetoresistance of nanogranular Ni/NiO controlled by exchange anisotropy

“…The mean grain size of the NiO phase was (1872) nm. The XRD analysis also detected Fe impurities (∼3 vol%), structured on a length scale of the order of 100 nm, originated from abrasion of the stainless steel vial and balls during the milling process, in general agreement with previous results [9].…”

“…In these Ni/NiO samples, the EB effect is originated by the exchange interaction at the interface between Ni nanocrystallite moments and the spins of such a glassy NiO component, resulting in an unidirectional exchange anisotropy for the Ni phase [8,9].…”

Interplay between magnetic anisotropies in CoAu and Co films and antidot arrays: effects on the spin configuration and hysteretic behavior

“…For instance, this occurs in metallic glasses prepared by ultrarapid quenching 11,12,13 as well as in materials subjected to mechanical milling. 14,15 In thin films a mechanical stress can be produced because of the bonding with the substrate. 16 Hence, the magnetoelastic anisotropy can be varied by controlling the field of internal and applied stresses acting on the system 17,18 , an approach that appears especially promising in the case of layered materials grown on flexible substrates.…”