Slow Magnetic Relaxation of [Et3NH]2Mn(CH3CN)4(H2O)2] [Mn10O4(biphen)4Br12] (biphen=2,2′-biphenoxide) at Very Low Temperature
作者： A.L. Barra , Andrea Caneschi , Dante Gatteschi , David P. Goldberg , Roberta Sessolici
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摘要: Abstract The high-field EPR spectra of a mixed valence cluster compound formula [Et 3 NH] 2 [Mn(CH CN) 4 (H O) ] [Mn 10 O (biphen) Br 12 confirm that the high-spin ground state ( S =12) has negative zero-field splitting, D =−0.037(1) cm −1 . reversal magnetization at low temperature should therefore overcome an energy barrier corresponding to ∣ , which corresponds ca. 7.7 K. Slow relaxation is detected below 1 K by ac magnetic susceptibility and characteristic time follows approximately Arrhenius law, where height 7.0 counterion, constituted manganese(II) complex, easily oxidized, aged samples seem contain amorphous Mn
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