Events

Physics Colloquium - Design of Perovskite Oxides Nanowires by Electrospinning: Electric Transport and Magnetic Properties

Time: Nov 06, 2015 (03:00 PM)
Location: Room 236 Parker Hall - Snacks at Allison Lab Room 200 at 2:45pm

Details:

J.W. Yoon

Department of Materials Science and Engineering, Dankook University, Cheonan, Chungnam 330-714, Korea

 

Perovskite-type oxides have been of great interest due to its multi-functionality for potential applications such as electromagnetic, catalytic, and sensing applications. Of them, orthoferrite LaFeO3 draws the attention due to its unique properties, e.g., antiferromagnetic and ferroelectric multi-ferroic behavior, catalytic activity for organic combustion, and high sensitivity for gas sensing at low temperature. On the other hand, nanowires have shown great potential as active building blocks for assembling a variety of nanoscale electronic and optical devices. While an extensive body of research exists on particles and films, far less is known about the characteristics in perovskite-type oxides nanowires, furthermore the properties and quality are stronly influenced by synthesis route and nanostructure. Recently, we first reported on the formation and magnetic behavior of perovskite LaFeO3 nanowires demonstrating that ferromagnetism can be induced due to uncompensated surface spins and/or internal spin canting, despite of very high Néel temperature of 740 K in bulk form. As extending the previous study, the research on electrical behaviors for nanowire devices can also serve a handle, potentially for a variety of advanced nanoelectronics using functionality of perovskite-type oxides. In this work, perovskite-type oxides, e.g., mutiferroic BiFeO3 nanowires with Mn doping and high conductive BaSnO3 with Sm doping can be produced by electrospinning, leading to the formation of specific nanostructure of linearly interconnected nanocrystallite array in nanowire framework. Furthermore, the structure and chemical state analyses for the perovskite-type oxides were performed to reveal the nanostructural difference caused by dopants substitution. The electric transport and magnetic measurement on the perovskite-type oxides nanowire device will be presented.