Year: 2025
Type: article
Abstract: Single-molecule magnets (SMMs) show promise for high-density data storage due to molecular-level magnetic hysteresis, but low-temperature quantum tunneling of magnetization (QTM) limits their blocking temperatures (TB), making QTM suppression critical. Herein, we report two dinuclear Er-cyclooctatetraenyl compounds: [K(18-C-6)(THF)][(COT1,4TMS2)Er(μ-Cl)₃Er(COT1,4TMS2)] (1) and [K(18-C-6)(THF)₂][(COT1,3TMS2)Er(μ-Br)₃Er(COT1,3TMS2)] (2) (COT1,4TMS2 and COT1,3TMS2 donate 1,4- and 1,3-bis(trimethylsilyl)-substituted cyclooctatetraenyl ligands, respectively; 18-C-6 = 18-Crown-6 ether). In both compounds, the two Er(III) ions are triply bridged by Cl− (1) or Br− (2). Ab initio calculations confirm strong axial anisotropy and ferromagnetic axial dipolar interactions from “head-to-tail” magnetic easy axes. Such axial dipolar interactions lead to the QTM being effectively suppressed by minimizing transverse dipolar fields, yielding hard magnetic behavior with open magnetic hysteresis loops up to 10 K and coercive fields of 6.25 kOe (1) and 4.75 kOe (2) at 2 K. These results demonstrate tunable halide-bridged dinuclear architectures for hard-magnetic SMMs via a non-radical approach. Single-molecule magnets offer potential for high-density data storage, but their low blocking temperatures due to quantum tunneling of magnetization (QTM) remain a challenge. Here, the authors synthesize two dinuclear Er-cyclooctatetraenyl compounds, demonstrating that strong axial dipolar interactions effectively suppress QTM, achieving hard magnetic behavior with open hysteresis loops up to 10 K.
Source: Communications Chemistry
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,690
OpenAlex ID: W4417154584