Slow relaxation of the magnetization observed in an antiferromagnetically ordered phase for SCM-based two-dimensional layered compounds

Koichi Kagesawa, Yuki Nishimura, Hiroki Yoshida, Brian K. Breedlove, Masahiro Yamashita, Hitoshi Miyasaka

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)

Abstract

Two-dimensional layered compounds with different counteranions, [{Mn(salen)}4C6](BF4)2·2(CH3OH) (1) and [{Mn(salen)}4C6](PF6)2·2(CH3OH) (2) (salen2− = N,N′-bis(salicylideneiminato), C62− = C6H12(COO)22−), were synthesized by assembling [Mn(salen)(H2O)]X (X = BF4 and PF6) and C6H12(CO2)2 (C62−) in a methanol/2-propanol medium. The compounds have similar structures, which are composed of Mn(salen) out-of-plane dimers bridged by μ4-type C62− ions, forming a brick-wall-type network of [-{Mn2}-OCO-] chains alternately connected via C6H12 linkers of C62− moieties. The counteranions for 1 and 2, i.e., BF4 and PF6, respectively, are located between layers. Since the size of BF4 is smaller than that of PF6, intra-layer inter-chain and inter-plane nearest-neighbor Mn⋯Mn distances are shorter in 1 than in 2. The zigzag chain moiety of [-{Mn2}-OCO-] leads to a canted S = 2 spin arrangement with ferromagnetic coupling in the MnIII out-of-plane dimer moiety and antiferromagnetic coupling through-OCO-bridges. Due to strong uniaxial anisotropy of the MnIII ion, the [-{Mn2}-OCO-] chains could behave as a single-chain magnet (SCM), which exhibits slow relaxation of magnetization at low temperatures. Nevertheless, these compounds fall into an antiferromagnetic ground state at higher temperatures of TN = 4.6 and 3.8 K for 1 and 2, respectively, than active temperatures for SCM behavior. The spin flip field at 1.8 K is 2.7 and 1.8 kOe for 1 and 2, respectively, which is attributed to the inter-chain interactions tuned by the size of the counteranions. The relaxation times of magnetization become longer at the boundary between the antiferromagnetic phase and the paramagnetic phase.

Original languageEnglish
Pages (from-to)3170-3178
Number of pages9
JournalDalton Transactions
Volume46
Issue number10
DOIs
Publication statusPublished - 2017

ASJC Scopus subject areas

  • Inorganic Chemistry

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