Tuning of exchange bias with interfacial ferromagnetism in NdNiO3/NdMnO3 heterostructures

Proximity‐Induced Novel Ferromagnetism Accompanied with Resolute Metallicity in NdNiO3 Heterostructure

“…The interfacial ferromagnetism previously was explained as consequences of a charge transfer from FM layer to Ni sites. [26,30] However, our study shows that it can be induced in the NNO primarily by the stray field from the LSMO layer, which aligns the spins at Ni sites. We demonstrate that, in addition to strain and film thickness, the proximity layer emerges as an additional "knob" for manipulating existing and inducing novel physical properties, consequently ameliorating the phase diagram of RENiO 3 .…”

“…[26,28] Moreover, various complex heterostructures created from NNO and other TMOs (CoFe 2 O 4 , LSMO, NdMnO 3 ) showed the emergence of interfacial ferromagnetism. [26,29,30] Therefore, it is crucial to disentangle the size effect from the interlayer charge transfer and potentially establish a link between the electronic structure (and MIT) and a magnetic ordering when the thin NNO film is magnetically perturbed.…”

Diamagnetic coupling for magnetic tuning in nano-thin films

“…Although the effect is fully understood, much research is currently dedicated to finding new ways to enhance and manipulate the exchange bias field. [4][5][6][7] Here, we show that diamagnetic coupling is a promising approach to fabricating magnetic hetero-structures and multilayers that can be used to significantly enhance the exchange bias effect. By using a diamagnetic underlayer for exchange bias structures, we were able to demonstrate that the negative magnetic susceptibility of the diamagnet reduces the effective positive magnetic susceptibility of the magnetic layer, enhancing significantly the overall exchange bias effect.…”

“…17 The best material choice in terms of largest diamagnetic susceptibility is Bi, v dia ¼ v Bi ¼ À16.6 Â 10 À5. 18 Using these numerical values in (6), we obtain the thickness of the diamagnetic underlayer required to produce a zero effective magnetic moment/ effective susceptibility, t dia ¼ 0.25 m. This thickness is very large, but most likely overestimated because the ferromagnet permalloy saturates at a relatively low magnetic field, while the diamagnet increases its magnetization linearly with the applied field, indefinite, without saturation. For a 7 nm soft ferromagnetic layer, saturating at 30 Oe magnetic field, we estimate that the required thickness of the Bi diamagnetic underlayer in order to achieve the total effective magnetic moment cancelation at 1000 Oe, is t dia ¼ 7.3 Â 10 À3 m. This thickness is still rather large, but the same coupling could be induced with much thinner diamagnetic layers, without achieving total cancelation of the effective magnetization.…”