Control of Defects and Magnetic Properties in Colloidal HfO2 Nanorods


  • The authors gratefully acknowledge the help of Dr. Alex Zunger throughout this work and thank Dr. Yossi Lereah for his help with HRTEM analysis. This research was supported by The Israel Science Foundation grant no. 779/06 and the James Frank program. Supporting information is available online from Wiley InterScience or from the authors.


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Colloidal HfO2nanorods with controllable defects are synthesized. An increased defect concentration is observed by high-resolution electron microscopy and by optical absorption spectroscopy. Nanocrystals with a high defect concentration exhibit ferromagnetism and superparamagnetic-like behavior (see figure). This low-temperature colloidal syntheses can produce the highly nonequilibrium defect concentrations needed to obtain ferromagnetism in closed shell oxides.