Observation of hysteretic magnetic phase transitions coupled with orientation motion of ions and dielectric relaxation in a one-dimensional nickel-bis-dithiolene molecule solid.
Observation of hysteretic magnetic phase transitions coupled with orientation motion of ions and dielectric relaxation in a one-dimensional nickel-bis-dithiolene molecule solid.
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DOI：
10.1039/c3dt53481b
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发表时间：
2014-03
影响因子：
4
通讯作者：
Xuan-Rong Chen;Wei-Hua Ning;Hao Yang;Jian‐Lan Liu;F. Xuan;X. Ren
中科院分区：
文献类型：
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作者：
Xuan-Rong Chen;Wei-Hua Ning;Hao Yang;Jian‐Lan Liu;F. Xuan;X. Ren
获得了镍-双二硫杂环戊烯化合物 [4'-CF3bzPy][Ni(mnt)2] 的第二种多晶型物，即 β 晶体，其中 4'-CF3bzPy = 1-(4'-三氟甲基苄基)吡啶鎓，mnt(2-) = 马来酰二硫醇盐。研究了β晶的变温单晶结构、1.8-300 K的磁行为和123-373 K的介电性质。该多晶型物在狭窄的温度范围（190-217 K）内经历两次磁滞磁相变，热滞回线约为 100°C。 6 K 和约。 11 K。两个磁滞磁相变分别与两个同构相变 (IPT) 耦合，它们是由 β 晶体中阴离子和阳离子的新型逐步动态取向运动驱动的。在结构转变温度区间不存在介电异常。然而，在高温阶段出现了与交流电场下阳离子中极性CF3基团的偶极子运动相关的介电弛豫。
The second polymorph, the β-crystal, of the nickel-bis-dithiolene compound [4'-CF3bzPy][Ni(mnt)2], where 4'-CF3bzPy = 1-(4'-trifluoromethylbenzyl)pyridinium and mnt(2-) = maleonitriledithiolate, was obtained. The variable-temperature single crystal structures, magnetic behavior in 1.8-300 K and dielectric nature in 123-373 K have been investigated for the β-crystal. This polymorph experiences two hysteretic magnetic phase transitions in a narrow temperature region (190-217 K) with the thermal hysteresis loops ca. 6 K and ca. 11 K. The two hysteretic magnetic phase transitions are coupled with two isostructural phase transitions (IPTs), respectively, which are driven by the novel step-wise dynamic orientation motion of the anion and cation in the β-crystal. There is an absence of a dielectric anomaly in the structural transformation temperature interval. However, a dielectric relaxation, related to the dipole motion of polar CF3 groups in the cations under an ac electrical field, emerges in the high-temperature phase.