Hole-injection induced magnetic enhancement in Cobalt-Ferrite encapsulated with amorphous-carbon

Jiann-Shing Lee¹, Shih-Min Hung¹, Chun-Rong Lin¹, Chi-Liang Chen², Jau-Wen Chiou³, Chih-Yu Hua², Huang-Ming Tsai², Way-Faung Pong⁴, Chien-Te Chen², Wen-Bin Wu², Jiunn Chen^1*

¹Department of Applied Physics, National Pingtung University, Pingtung, Taiwan
²National Synchrotron Radiation Research Center, National Synchrotron Radiation Research Center, Hsinchu, Taiwan
³Department of Applied Physics, National University of Kaohsiung, Kaohsiung, Taiwan
⁴Department of Physics, Tamkang University, New Taipei City, Taiwan

* Presenter:Jiunn Chen, email:asesrrc@gmail.com

Magnetic enhancement upto 25% was observed from the carbon encapsulated cobalt ferrite nanoparticles. Hole injections with the increasing carbon reactant was concluded from the Co L-edge absorptions which show systematic blue shift of the lowest-lying final states apart from the coordination symmetry. X-ray magnetic circular dichroism identified the octahedral Co2+ ions as hole acceptor degendered the magnetic enhancement. Spin-split electronic structure of cobalt-ferrite based on DFT+U demonstrate the hole reservoir, octahedral Co ions, control the magnetic properties of the hybrid system.

Keywords: cobalt-ferrite, x-ray absorption, first-principle calculations, magnetic enhancement