Vishnoi Pratap, Zuo Julia L, Cooley Joya A, Kautzsch Linus, Gómez-Torres Alejandra, Murillo Jesse, Fortier Skye, Wilson Stephen D, Seshadri Ram, Cheetham Anthony K
Materials Department and Materials Research Laboratory, University of California, Santa Barbara, CA, 93106, USA.
Department of Chemistry and Biochemistry, California State University, Fullerton, CA, 92831, USA.
Angew Chem Int Ed Engl. 2021 Mar 1;60(10):5184-5188. doi: 10.1002/anie.202013383. Epub 2021 Jan 15.
Vacancy-ordered double perovskites are attracting significant attention due to their chemical diversity and interesting optoelectronic properties. With a view to understanding both the optical and magnetic properties of these compounds, two series of Ru halides are presented; A RuCl and A RuBr , where A is K, NH , Rb or Cs. We show that the optical properties and spin-orbit coupling (SOC) behavior can be tuned through changing the A cation and the halide. Within a series, the energy of the ligand-to-metal charge transfer increases as the unit cell expands with the larger A cation, and the band gaps are higher for the respective chlorides than for the bromides. The magnetic moments of the systems are temperature dependent due to a non-magnetic ground state with J =0 caused by SOC. Ru-X covalency, and consequently, the delocalization of metal d-electrons, result in systematic trends of the SOC constants due to variations in the A cation and the halide anion.
空位有序双钙钛矿因其化学多样性和有趣的光电特性而备受关注。为了理解这些化合物的光学和磁性性质，我们展示了两个系列的钌卤化物；A RuCl和A RuBr，其中A为K、NH、Rb或Cs。我们表明，通过改变A阳离子和卤化物，可以调节光学性质和自旋轨道耦合（SOC）行为。在一个系列中，随着晶胞随着较大的A阳离子而膨胀，配体到金属的电荷转移能量增加，相应氯化物的带隙高于溴化物。由于SOC导致的J = 0的非磁性基态，系统的磁矩与温度有关。Ru-X共价性以及金属d电子的离域，由于A阳离子和卤化物阴离子的变化，导致SOC常数呈现系统趋势。
