论文标题
场诱导基于Dy的配位聚合物中的单分子磁铁行为
Field induced single molecule magnet behavior in Dy-based coordination polymer
论文作者
论文摘要
使用DC和AC磁敏感性研究了一种新的基于单单核差的配位聚合物{DY-CP}。直流磁敏感性不会显示出任何远距离排序降低至1.8 K，而居里常数（〜 -4 K）的负值表示DY（III）旋转之间的抗磁相互作用的优势。 AC易感性在零DC磁场上表现出缺乏单分子磁铁行为，并显示出低于8 K的量子隧穿磁化（QTM）的信号。但是，在DC磁场的叠加（3 KOE）上，频率依赖的弛豫峰在T_F = 5 K和QTM信号抑制在较高场上。 MyDosh参数的中间值是根据AC敏感性中峰位置（T_F）移动计算得出的，这反映了超paragnetic态的形成。此外，用Arrhenius和Cole-Cole图分析了TF的温度依赖性。磁化率分析产生的特征前暂停因子1.40x10^（-12）sec和能屏障ΔE/k_b = 93.4 K，表明缓慢自旋松弛。 Cole-Cole拟合AC敏感性数据显示了单个离子自旋松弛的进一步证据。因此，在DC磁场的应用下，磁性测量支持DY-CP中的单分子磁铁行为。
A new mononuclear Dysprosium based Coordination Polymer {Dy-CP} was investigated magnetically using dc and ac magnetic susceptibility. The dc magnetic susceptibility does not exhibit any long-range ordering down to 1.8 K and the negative value of Curie Constant (~ - 4 K) indicate the dominance of antiferromagnetic interactions between the Dy (III) spins. Ac susceptibility exhibits absence of single molecular magnet behavior at zero dc magnetic field and shows signal of quantum tunneling magnetization (QTM) below 8 K. However, on the superimposition of dc magnetic field (3 kOe), frequency dependent relaxation peak emerged at T_f = 5 K and QTM signal suppress at higher fields. The intermediate value of Mydosh parameter calculated from the shift in peak position (T_f) in ac susceptibility reflects the formation of superparamagnetic state. Further, the temperature dependence of Tf is analyzed with Arrhenius and Cole-Cole plot. The magnetic susceptibility analysis yields characteristics pre-relaxation factor 1.40x10^(-12) sec and energy barrier ΔE/k_B = 93.4 K, indicating the slow spin relaxation. The Cole-Cole fit to the ac susceptibility data shows further evidence for the single ion spin relaxation. Thus, the magnetic measurements support the single-molecule magnet behavior in Dy-CP under the application of dc magnetic field.
