EPR characterization of half-integer-spin iron molecule-based magnets

详细信息    查看全文

• 作者：Saiti Datta ; Amalia Betancur-Rodriguez ; Sheng-Chiang Lee ; Stephen Hill ; Dolos Foguet-Albiol ; Rashmi Bagai ; George Christou
• 关键词：Single-molecule magnets ; Nanomagnet ; Electron paramagnetic resonance ; Quantum tunneling ; Iron
• 刊名：Polyhedron
• 出版年：2007
• 出版时间：15 June 2007
• 年：2007
• 卷：26
• 期：9-11
• 页码：2243-2246
• 全文大小：548 K

文摘

We report single crystal high-frequency electron paramagnetic resonance studies of two recently discovered half-integer Fe₇ complexes: [Fe₇O₃(O₂CBu^t)₉(mda)₃(H₂O)₃] (1) and [Fe₇O₄(O₂CPh)₁₁(dmem)₂] (2). The obtained spectra confirm spin S = 5/2 ground states for both complexes. On the basis of detailed frequency and field orientation dependent studies, we find that complex 1 is a single-molecule magnet (uniaxial zero-field-splitting parameter, D < 0) while complex 2 is not (D > 0). The EPR linewidth for complex 1 is considerably narrower in comparison to spectra obtained for other single-molecule magnets, suggesting the possibility of reduced decoherence from nuclear spins (⁵⁶Fe has no nuclear moment).