Probing Magnetic Excitations in Co II Single-Molecule Magnets by Inelastic Neutron Scattering: Probing Magnetic Excitations in Co II Single-Molecule Magnets by Inelastic Neutron Scattering
Probing Magnetic Excitations in Co II Single-Molecule Magnets by Inelastic Neutron Scattering: Probing Magnetic Excitations in Co II Single-Molecule Magnets by Inelastic Neutron Scattering
复制标题
通过非弹性中子散射探测 Co II 单分子磁体中的磁激发：通过非弹性中子散射探测 Co II 单分子磁体中的磁激发
DOI：
10.1002/ejic.201801088
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发表时间：
2019
影响因子：
2.3
通讯作者：
Xue, Zi-Ling
中科院分区：
文献类型：
--
作者：
Stavretis, Shelby E.;Cheng, Yongqiang;Daemen, Luke L.;Brown, Craig M.;Moseley, Duncan H.;Bill, Eckhard;Atanasov, Mihail;Ramirez-Cuesta, Anibal J.;Neese, Frank;Xue, Zi-Ling
Co(acac)2(H2O)2(1，acac = 乙酰丙酮)是一种过渡金属络合物 (S= 3/2)，作为单分子磁体表现出场诱导的慢磁弛豫。对于 1 及其同位素异构体 Co(acac)2(D2O)2(1‐d4) 和 Co(acac‐d7)2(D2O)2(1‐d18) 近似 D4h 对称性，基态电子态的零场分裂导致两个克莱默双峰 (KD)：较低能量 MS= ±1/2 (phi1,2) 和较高能量 MS= ±3/2 (φ3,4) 状态。这项工作采用非弹性中子散射 (INS)（一种探测磁转变的独特方法）来探测 1-d4 和 1-d18 中的不同磁激发。直接几何飞行时间圆盘斩波光谱仪 (DCS)，施加高达 10 T 的磁场，已用于研究塞曼分裂导致的 KD 内转变，MS= –1/2 (φ1) →MS= +1/2 (φ2)，in1-d18。这是对 INS 过渡金属配合物中 MS= –1/2 →MS= +1/2 激发的罕见研究。间接几何 INS 光谱仪 VISION 已被用来探测 1-d4 和 1-d18 中的 KD、ZFS 间跃迁，通过这种激发的变温 (VT) 特性，MS= ±1/2 (Φ1,2) →MS= ±3/2 (Φ3,4)。在 VISION 上测量的 INS 谱还给出了配合物的声子特征，这些特征可以通过周期性 DFT 声子计算得到很好的描述。
Co(acac)2(H2O)2(1, acac = acetylacetonate), a transition metal complex (S= 3/2), displays field‐induced slow magnetic relaxation as a single‐molecule magnet. For1and its isotopologues Co(acac)2(D2O)2(1‐d4) and Co(acac‐d7)2(D2O)2(1‐d18) in approximatelyD4hsymmetry, zero‐field splitting of the ground electronic state leads to two Kramers doublets (KDs): lower energyMS= ±1/2 (ϕ1,2) and higher energyMS= ±3/2 (ϕ3,4) states. This work employs inelastic neutron scattering (INS), a unique method to probe magnetic transitions, to probe different magnetic excitations in1‐d4and1‐d18. Direct‐geometry, time‐of‐flight Disk‐Chopper Spectrometer (DCS), with applied magnetic fields up to 10 T, has been used to study the intra‐KD transition as a result of Zeeman splitting,MS= –1/2 (ϕ1) →MS= +1/2 (ϕ2), in1‐d18. This is a rare study of theMS= –1/2 →MS= +1/2 excitation in transition metal complexes by INS. Indirect‐geometry INS spectrometer VISION has been used to probe the inter‐KD, ZFS transition,MS= ±1/2 (ϕ1,2) →MS= ±3/2 (ϕ3,4) in both1‐d4and1‐d18, by variable‐temperature (VT) properties of this excitation. The INS spectra measured on VISION also give phonon features of the complexes that are well described by periodic DFT phonon calculations.