Single-molecule magnet behavior enhanced by magnetic coupling between 4f and 3d spins

We synthesized and characterized a new compound [{Dy(hfac)3}2Pd(dpk)2] ([Dy2Pd]; Hdpk = di-2-pyridyl ketoxime), which is isostructural with the known [Dy2Cu] and [Dy2Ni]. The study of the [Dy2Pd] compound containing diamagnetic Pd ion is indispensable to clarify a contribution of the exchange coupling for a 4f–3d single-molecule magnet behavior. From the ac susceptibility measurements on [Dy2Pd], we obtained Δ/kB = 28.6(11) K and TB = 1.1 K. In accordance with the blocking behavior, the pulsed-field magnetization showed the hysteresis behavior below 1.1 K. These parameters on [Dy2Pd] having SPd = 0 was compared with those of the derivatives having SCu = 1/2 (Δ/kB = 47 K and TB = 1.8 K) and SNi = 1 (Δ/kB = 62(4) K and TB = 2.5 K). The TB and Δ steadily increase with the increasing 3d(4d) spin quantum number.

A new compound [Dy2Pd] was characterized to be an SMM with TB = 1.1 K and Δ/kB = 28.6(11) K. The role of the 3d(4d) spin in the SMM performance is discussed after comparison among the results on [Dy2Cu] and [Dy2Ni].Figure optionsDownload as PowerPoint slideHighlights
► A novel trinuclear single-molecule magnet [Dy2Pd] was synthesized.
► The order of the SMM performance is: [Dy2Ni] > [Dy2Cu] > [Dy2Pd].
► The importance of 4f−3d magnetic couplings was demonstrated.