Unraveling the mark of surface defects on a spinterface： The nitronyl nitroxide/TiO2（110） interface  

作　　者：Reza Kakavandi Arrigo Calzolari Yulia B. Borozdina Prince Ravat Thomas Chasse Martin Baumgarten M. Benedetta Casu 

机构地区：[1]Institute of Physical and Theoretical Chemistry, University of Tubingen, Auf der Morgenstelle 18, 72076 Tubingen, Germany [2]CNR-NANO Istituto Nanoscienze, Centro S3, 41125 Modena, Italy [3]Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany

出　　处：《Nano Research》2016年第11期3515-3527,共13页纳米研究（英文版）

摘　　要：Metal-free organic radicals are fascinating materials owing to their unique properties. Having a stable magnetic moment coupled to light elements makes these materials central to develop a large variety of applications. We investigated the magnetic spinterface coupling between the surface of a single rutile TiO2（110） crystal and a pyrene-based nitronyl nitroxide radical, using a combination of thickness-dependent X-ray photoelectron spectroscopy and ab initio calculations. The radicals were physisorbed, and their magnetic character was preserved on the （almost） ideal surface. The situation changed completely when the molecules interacted with a surface defect site upon adsorption. In this case, the reactivity of the defect site led to the quenching of the molecular magnetic moment. Our work elucidates the crucial role played by the surface defects and demonstrates that photoemission spectroscopy combined with density functional theory calculations can be used to shed light on the mechanisms governing complex interfaces, such as those between magnetic molecules and metal oxides.Metal-free organic radicals are fascinating materials owing to their unique properties. Having a stable magnetic moment coupled to light elements makes these materials central to develop a large variety of applications. We investigated the magnetic spinterface coupling between the surface of a single rutile TiO2（110） crystal and a pyrene-based nitronyl nitroxide radical, using a combination of thickness-dependent X-ray photoelectron spectroscopy and ab initio calculations. The radicals were physisorbed, and their magnetic character was preserved on the （almost） ideal surface. The situation changed completely when the molecules interacted with a surface defect site upon adsorption. In this case, the reactivity of the defect site led to the quenching of the molecular magnetic moment. Our work elucidates the crucial role played by the surface defects and demonstrates that photoemission spectroscopy combined with density functional theory calculations can be used to shed light on the mechanisms governing complex interfaces, such as those between magnetic molecules and metal oxides.

关 键 词：organic spinterface photoemission spectroscop density functional theory calculations 

分 类 号：O[理学]