Effective distance of a ferromagnetic trilayer Ising nanostructure with an ABA stacking sequence

• We studied the magnetic properties of a trilayer Ising nanostructure (TLINS).
• Magnetic properties of TLINS depend greatly on the distance between layers.
• We suggest that there is an effective distance (deff) between the layers.
• Interaction between layers is strong at d≤deff but almost zero at d≥deff.
• HCHC and TCTC are independent of the distance and almost constant at d≥deff.

In this study, we investigated the effects of the distance between two nearest-neighbor layers on the magnetization and hysteresis properties (remanence, coercivity and loop area) of a ferromagnetic trilayer Ising nanostructure (TLINS) with an ABA stacking sequence using the Kaneyoshi approach within the effective field theory. We found that the ferromagnetic properties of the TLINS were highly dependent on the distance (d)(d) between the layers. The layers had strong interactions at a certain minimum distance (dmin) ​but no interactions at a certain maximum distance (dmax). Thus, we suggest that there is an effective distance (deff) at dmin≤deff≤dmax for the TLINS. We observed that the critical temperature increased sharply as the distance decreased at d≤dmin,TC ​ increased slowly as the distance decreased at  deff, and TCTC ​had a certain constant value at d≥dmax. The critical field points increased rapidly as the distance decreased and HCHC ​had different values for the central and edge atoms at d≤dmin. HCHC ​increased slowly as the distance decreased at deff and HCHC ​had the same value for the central and edge atoms at deff, while HCHC ​had a certain constant value at d≥dmax. Distance had no effect on the critical temperature and critical field points of the TLINS and they had a constant value at d≥dmax; thus, the TLINS behaved as a single layer Ising nanostructure at great distances.