Creation of Switching Systems of Superparamagnets by External Stimulus

我们这个项目的目的是通过与外部刺激切换来在超顺磁网中创建新的物理属性和功能。我们采用的一种策略是制备像[Pc_2Tb]Cl0.6这样的导电SMM，它的阻断温度为47K，其磁特性在10K以下表现出滞后。在我们的第二个策略中，我们将平面存储器引入双层Tb(III)SMM(Pc_2Tb)中。此外，我们还首次利用扫描隧道谱(STS)观察到了4.8K的近藤效应。我们可以通过使用STS注入一个电子来控制近藤峰的出现和消失。这被认为是第一个单分子存储器件。在我们的第三个策略中，我们制备了SMM的场效应晶体管(FET)器件。Pc2Dy器件表现出双极(n型和p型)行为，而Pc2Tb器件表现出p型行为。这种差异可以用稀土离子的能级来解释。在第四种策略中，我们将Cs原子掺杂到Pc_2Y上。虽然Pc_2Y分子由于Pc配体中未配对的自旋而显示出Kondo峰，但当掺杂时，由于Pc基团和Cs原子的6S电子的耦合，没有观察到Kondo峰。最后，通过掺杂和操纵Cs原子，我们可以写出字母T和U，这是东北大学的首字母。

Our purposes of this project are to create the new physical properties and functionalities in superparamagnets by switched with the external stimulus. One strategy that we have employed is to prepare conducting SMMs, like [Pc_2Tb]Cl_0.6, which has a blocking temperature of 47K and whose magnetic properties showed hysteresis below 10K. This SMM shows negative magnetoresistance below 8 K. In our second strategy, we have incorporated planar memory into a double-decker Tb(III) SMM (Pc_2Tb). In addition, we have observed a Kondo Effect at 4.8 K by using scanning tunneling spectroscopy (STS) for the first time. We can control the appearance and disappearance of the Kondo peak by injecting an electron using an STS. This is considered to be the first single-molecule memory device. In our third strategy, we have prepared field effect transistor (FET) devices of SMMs. The Pc2Dy device shows ambipolar (n- and p-type) behavior, whereas the Pc2Tb device shows p-type behavior. This difference is explained by the energy levels of the lanthanide ions. In the fourth strategy, we have doped Cs atoms onto Pc_2Y. Although Pc_2Y molecules show Kondo peaks due to the unpaired spin in the Pc ligand, when doped, Kondo peaks are not observed due to coupling of the radical Pc and the 6s electrons of the Cs atom. Finally, by doping with and manipulating the Cs atoms, we could write the letters T and U, which are the initials of Tohoku University.