Unusual Magnetic Response of an S = 1 Antiferromagetic Linear-Chain Material
Unusual Magnetic Response of an S = 1 Antiferromagetic Linear-Chain Material
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DOI：
10.1088/1742-6596/969/1/012121
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发表时间：
2014-09
期刊：
影响因子：
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通讯作者：
J. Xia;A. Ożarowski;P. Spurgeon;Adora G. Graham;J. Manson;M. Meisel
中科院分区：
文献类型：
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作者：
J. Xia;A. Ożarowski;P. Spurgeon;Adora G. Graham;J. Manson;M. Meisel
S=1反铁磁聚合物链，[Ni(Hf_2)(3-Clpy)_4]BF_4(Py=吡啶)，以前已被确定具有链内最近邻的反铁磁相互作用强度J/kB=4.86K和单离子各向异性(零场分裂)D/kB=4.3K，因此D/J=0.88使该体系接近于具有不同拓扑结构的Haldane相和大D相之间的D/J≈1无间隙临界点。在50mK≤T≤1K的温度范围和B≤10T的磁场范围内研究了磁化强度，试图确定与间隙关闭相关的临界场BC，本工作给出了BC≤(35±10)mT的上界。在较高的磁场下，观测到的磁响应定性上类似于其他工作人员在0.5K和低于3T时观察到的“过剩”信号。在3K时的高场(高达14.5T)、多频率(名义上为200 GHz至425 GHz)ESR谱揭示了与样品相关的几个特征。
An S = 1 antiferromagnetic polymeric chain, [Ni(HF2)(3-Clpy)4]BF4 (py = pyridine), also referred to as NBCT, has previously been identified to have intrachain, nearest-neighbor antiferromagnetic interaction strength J/kB = 4.86 K and single-ion anisotropy (zero-field splitting) D/kB = 4.3 K, so the ratio D/J = 0.88 places this system close to the D/J ≈ 1 gapless critical point between the topologically distinct Haldane and Large-D phases. The magnetization was studied over a range of temperatures, 50 mK ≤ T ≤ 1 K, and magnetic fields, B ≤ 10 T, in an attempt to identify a critical field, Bc, associated with the closing of a gap, and the present work places an upper bound of Bc ≤ (35 ± 10) mT. At higher fields, the observed magnetic response is qualitatively similar to the “excess” signal observed by other workers at 0.5 K and below 3 T. The high-field (up to 14.5 T), multi-frequency (nominally 200 GHz to 425 GHz) ESR spectra at 3 K reveal several features associated with the sample.