Single Ion Magnets from 3d to 5f: Developments and Strategies

Abstract

Single-ion magnets (SIMs), exhibiting slow magnetization relaxation in the absence of the magnetic field, originate from their single spin-carrier centre. In pursuit of high-performance magnetic properties, such as high spin-reversal barrier and high blocking temperature, various metal centres were investigated to establish SIMs, including 3d and 5d transition metal ions, 4f lanthanide ions, and 5f actinide ions, which possess unique zero-field splitting and magnetic properties. Therefore, proper ligand field is of great importance to different types of metals. In the given great breakthroughs since the first SIM, [Pc Tb] (Pc=dianion of phthalocyanine), was reported, strategies of ligand field design have emerged. In this review, the developments of SIMs with different metal centres are summarized, as well as the possible strategies.

Slow Magnetic Relaxation, Antiferromagnetic Ordering, and Metamagnetism in MnII(H2dapsc)‐FeIII(CN)6Chain Complex with Highly Anisotropic Fe‐CN‐Mn Spin Coupling

“…In particular, these efforts have resulted in the discovery of the first mononuclear SMMs (so‐called single‐ion magnets, SIMs) based on lanthanide ions. [ 6] Currently, the record energy barriers and blocking temperatures for SMMs are held by lanthanide complexes –. In this respect, the use of special ligands producing a less‐common coordination represents an efficient way to increase magnetic anisotropy, which is strongly influenced by the coordination environment of the metal centers; the local magnetic anisotropy can be enhanced by a proper tuning of the ligand's geometry –.…”

Field-induced slow relaxation of magnetization in the S = 3/2 octahedral complexes trans-[Co{(OPPh2)(EPPh2)N}2(dmf)2], E = S, Se: effects of Co–Se vs. Co–S coordination

“…A trigonal pyramidal high spin Fe(II) complex is the first 3d metal-based mononuclear complex shown to exhibit field-induced slow relaxation of its magnetization. 25 Following that report, slow relaxation of magnetization has been established for complexes of Cr(II), Mn(III), Mn(IV), Fe(I), Fe(II), Fe(III), Co(I), Co(II), Ni(I), Ni(II), Cu(II), Cu(III), Re(IV), [19][20][21][22] and more recently of V(IV), 26,27 Mn(II) 28,29 and Ru(III). 30 Complexes of Co(II) constitute the largest family of 3dmetal-based complexes showing slow relaxation of their magnetization.…”

“…In an effort to master a synthetic control over the magnitude of D, a large number of 3d-based mononuclear complexes have been under extensive experimental [19][20][21][22] or computational 23,24 investigation. A trigonal pyramidal high spin Fe(II) complex is the first 3d metal-based mononuclear complex shown to exhibit field-induced slow relaxation of its magnetization.…”

161Dy Time‐Domain Synchrotron Mössbauer Spectroscopy for Investigating Single‐Molecule Magnets Incorporating Dy Ions

“…This study demonstrates that 161 Dy SMS is an effective local probe of the influence of the coordinating ligands on the magnetic structure of Dy-containing compounds.The development of single-molecule magnets (SMMs), which show slow relaxation of their magnetization as aresult of abarrier height for spin inversion, [1][2][3][4] has attracted increasing interest in recent years due to the quantum nature with potential applications envisaged in spintronics and quantum computing. The magnetic hyperfine field of [Dy(Cy 3 PO) 2 (H 2 O) 5 ]Br 3 ·2 (Cy 3 PO)·2 H 2 O·2 EtOH is with B 0 = 582.3(5) Ts ignificantly larger than that of the free-ion Dy III with a 6 H 15/2 ground state.This difference is attributed to the influence of the coordinating ligands on the Fermi contact interaction between the sand 4f electrons of the Dy III ion.…”

“…The development of single-molecule magnets (SMMs), which show slow relaxation of their magnetization as aresult of abarrier height for spin inversion, [1][2][3][4] has attracted increasing interest in recent years due to the quantum nature with potential applications envisaged in spintronics and quantum computing. [5] Because of their large magnetic moments and their strong magnetic anisotropy,l anthanide ions in suitable ligand fields are ideal candidates for SMMs.…”