Doping Controls Plasmonics, Electrical Conductivity, and Carrier-Mediated Magnetic Coupling in Fe and Sn Codoped In2O3 Nanocrystals: Local Structure Is the Key

作者：Shanker G Shiva; Tandon Bharat; Shibata Tomohiro; Chattopadhyay Soma; Nag Angshuman^*

来源：Chemistry of Materials, 2015, 27(3): 892-900.

DOI：10.1021/cm5048936

Multifunctional FeSn codoped In(2)O3 colloidal nanocrystals simultaneously exhibiting localized surface plasmon resonance band, high electrical conductivity, and charge mediated magnetic coupling have been developed. Interactions between Sn and Fe dopant ions have been found critical to control all these properties. Sn doping slowly releases free electrons in the colloidal nanocrystals, after reduction of active complex between Sn4+ and interstitial O-2. Unexpectedly, Fe codoping reduces the free electron concentration. Our X-ray absorption fine structure spectroscopy (XAFS) results show that Fe3+ and Sn4+ substitutes In3+ in the In2O3 lattice for all Fe-doped In2O3 NCs and Sn-doped In2O3 NCs. Interestingly, for FeSn codoped NCs, a smaller fraction of Fe2+ gets reduced to Fe2+ by consuming free electrons produced by Sn doping. Therefore, Fe doping can manipulate free electron concentration in FeSn codoped In2O3 nanocrystals, controlling both plasmonic band and electrical conductivity. Free electrons, on the other hand, facilitate magnetic coupling between distant Fe3+ ions. Such charge mediated magnetic coupling is useful for spin-based applications.

• 出版日期2015-2-10