Chikara Shalinee, Gu Jie, Zhang X-G, Cheng Hai-Ping, Smythe Nathan, Singleton John, Scott Brian, Krenkel Elizabeth, Eckert Jim, Zapf Vivien S
National High Magnetic Field Lab (NHMFL), Los Alamos National Lab (LANL), Los Alamos, NM, 87545, USA.
University of Florida, Gainesville, FL, 32611, USA.
Nat Commun. 2019 Sep 6;10(1):4043. doi: 10.1038/s41467-019-11967-3.
In magnetoelectric materials, magnetic and dielectric/ferroelectric properties couple to each other. This coupling could enable lower power consumption and new functionalities in devices such as sensors, memories and transducers, since voltages instead of electric currents are sensing and controlling the magnetic state. We explore a different approach to magnetoelectric coupling in which we use the magnetic spin state instead of the more traditional ferro or antiferromagnetic order to couple to electric properties. In our molecular compound, magnetic field induces a spin crossover from the S = 1 to the S = 2 state of Mn, which in turn generates molecular distortions and electric dipoles. These dipoles couple to the magnetic easy axis, and form different polar, antipolar and paraelectric phases vs magnetic field and temperature. Spin crossover compounds are a large class of materials where the spin state can modify the structure, and here we demonstrate that this is a route to magnetoelectric coupling.
在磁电材料中，磁性与介电/铁电特性相互耦合。这种耦合能够在诸如传感器、存储器和换能器等器件中实现更低的功耗以及新功能，因为是电压而非电流在传感和控制磁状态。我们探索了一种不同的磁电耦合方法，即利用磁自旋态而非更传统的铁磁或反铁磁序来与电特性耦合。在我们的分子化合物中，磁场会诱导锰从S = 1态自旋交叉到S = 2态，这反过来又会产生分子畸变和电偶极子。这些偶极子与易磁轴耦合，并相对于磁场和温度形成不同的极性、反极性和顺电相。自旋交叉化合物是一大类材料，其自旋态能够改变结构，在此我们证明这是一种磁电耦合的途径。
