Magnetic field-induced spin-crossover transition in [MnIII(taa)] studied by x-ray absorption spectroscopy
Magnetic field-induced spin-crossover transition in [MnIII(taa)] studied by x-ray absorption spectroscopy
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DOI：
10.1063/1.3691608
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发表时间：
2012-03
影响因子：
3.2
通讯作者：
J. Her;Y. Matsuda;M. Nakano;Y. Niwa;Y. Inada
中科院分区：
文献类型：
--
作者：
J. Her;Y. Matsuda;M. Nakano;Y. Niwa;Y. Inada
研究了自旋交叉化合物[MnIII（taa）]中Mn在高达37 T的脉冲强磁场中的X射线吸收近边结构（XANES）谱。XANES谱的显著变化与从低自旋（LS）态到高自旋（HS）态的自旋交叉有关，被发现是由温度低至17 K的磁场引起的。场诱导HS状态的分数是，最多，30%，和磁场的HS分数的依赖表现出滞后。在T = 17 K（T/Tc = 0.4，其中Tc（= 46 K）是自旋交叉转变温度）下观察到的场诱导自旋交叉不能被理解为场诱导宏观相变，因为已知在低温下转变磁场高于55 T。观察到的场诱导的LS-HS跃迁可能是单分子水平上的局域微观跃迁。
X-ray absorption near-edge structure (XANES) spectra of Mn in a spin-crossover compound, [MnIII(taa)], was studied in pulsed high magnetic fields up to 37 T. The significant changes in the XANES spectra, related to the spin-crossover from the low-spin (LS) state to high-spin (HS) state, were found to be induced by magnetic fields at temperatures down to 17 K. The fraction of the field-induced HS states was, at most, 30%, and the magnetic field dependence of the HS fraction exhibited hysteresis. The observed field-induced spin-crossover at T = 17 K (T/Tc ∼ 0.4, where Tc (= 46 K) is the spin-crossover transition temperature) cannot be understood as the field-induced macroscopic phase transition, because the transition magnetic field is known to be higher than 55 T at low temperatures. The observed field-induced LS-HS transition is likely the local microscopic transition at the single-molecule level.