Quenching points of dimeric single-molecule magnets: Exchange interaction effects

We study the quenched energy-splitting (ΔE) of a single-molecule magnet (SMM) conformed by two exchange coupled giant-spins. An assessment of two nontrivial characteristics of this quenching is presented: (i) The quenching-points of a strongly exchange-coupled dimer differ from the ones of their respective giant-spin modeled SMM and such a difference can be well described by using the Solari-Kochetov extra phase; (ii) the dependence on the exchange coupling of the magnetic field values at the quenching-points when ΔE passes from monomeric to dimeric behavior. The physics behind these exchange-modified points, their relation with the ΔE-oscillations experimentally obtained by the Landau-Zener method and with the diabolical-plane of a SMM, is discussed.