Department of Chemistry, University of North Bengal, Siliguri, PIN. 734013, Dist. Darjeeling, West Bengal, India.
J Phys Chem A. 2010 Feb 4;114(4):2022-7. doi: 10.1021/jp910661g.
Magnetization reversal is important for different technological applications. Photoinduced magnetization reversal is easier to implement than conventional reversal methods. Here, we theoretically design and investigate the photomagnetic property of azobenzene based diradical systems, where trans isomers convert into corresponding cis forms upon irradiation with light of appropriate wavelength. The coupling constant values have been estimated using the broken symmetry approach in the density functional theory framework. In each case, the trans isomer is found to be antiferromagnetic, while the cis form is ferromagnetic in nature. Therefore, photoinduced magnetic crossover from antiferromagnetic to ferromagnetic regime would be observed. This is a new observation in case of the systems of organic origin. Importance of such systems for photomagnetic switches, sensors, high density data storage, spin valves, and semiconductor spintronic materials have also been discussed with support from density of state analysis, singly occupied molecular orbital-singly occupied molecular orbital energy gaps and spin density plots.
磁化反转对于不同的技术应用很重要。光致磁化反转比传统的反转方法更容易实现。在这里，我们从理论上设计和研究了基于偶氮苯的双自由基体系的光磁性质，其中反式异构体在适当波长光的照射下转化为相应的顺式形式。利用密度泛函理论框架中的非对称破坏方法估计了耦合常数值。在每种情况下，反式异构体都是反铁磁的，而顺式形式本质上是铁磁的。因此，会观察到光诱导的从反铁磁到铁磁状态的磁交叉。对于有机起源的体系来说，这是一个新的观察结果。从态密度分析、单占据分子轨道-单占据分子轨道能隙和自旋密度图的角度讨论了这类体系在光磁开关、传感器、高密度数据存储、自旋阀和半导体自旋电子材料中的重要性。
