Study of the local field distribution on a single-molecule magnet by a single paramagnetic crystal: A DPPH crystal on the surface of an Mn12-acetate crystal
Study of the local field distribution on a single-molecule magnet by a single paramagnetic crystal: A DPPH crystal on the surface of an Mn12-acetate crystal
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单一顺磁晶体对单分子磁体局部场分布的研究：Mn12-醋酸盐晶体表面的DPPH晶体
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
N. Dalal
中科院分区：
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作者：
D. Žilić;B. Rakvin;N. Dalal
研究了在极短时间内(~10-10s)探测到的高于阻断温度(T≫Tb)的单分子磁体晶体表面的局域磁场分布。使用局部顺磁探针的电子顺磁共振(EPR)光谱被用作一种简单的替代检测方法。选择了[Mn12O12(CH3COO)16(H2O)4]·2CH3COOH·4H2O(Mn12-乙酸酯)SMM晶体和2，2-二苯基-1-苦基肼(DPPH)晶体作为顺磁探针。与没有SMM晶体沉积的DPPH相比，沉积在Mn12-醋酸酯上的DPPH的EPR谱在磁场中表现出额外的展宽和位移。根据两种主要的电子自旋相互作用(偶极相互作用和交换相互作用)和晶体表面的局域磁场分布，考虑了DPPH线宽的额外加宽。给出了S场局域场的高斯分布线宽随温度的变化关系。
The local magnetic field distribution on the surface of a single-molecule magnet crystal (SMM) above blocking temperature (T≫Tb) detected for a very short time interval (~10-10s), has been investigated. Electron paramagnetic resonance (EPR) spectroscopy, using a local paramagnetic probe, was employed as a simple alternative detection method. An SMM crystal of [Mn12O12(CH3COO)16(H2O)4]·2CH3COOH·4H2O (Mn12-acetate) and a crystal of 2,2-diphenyl-1-picrylhydrazyl (DPPH), as the paramagnetic probe, were chosen for this study. The EPR spectra of DPPH deposited on Mn12-acetate show additional broadening and shifting in the magnetic field in comparison to the spectra of the DPPH in the absence of the SMM crystal. The additional broadening of the DPPH linewidth was considered in terms of the two dominant electron spin interactions (dipolar and exchange) and the local magnetic field distribution on the crystal surface. The temperature dependence of the linewidth of the Gaussian distribution of local fields at the S...