Fabrication and emission characteristics for a single magnetite whisker

In this study, a spin-polarized electron source which can operate at room temperature is reported. <110>-oriented single crystal magnetite whiskers 30 to 200 nm in diameter were synthesized on a stainless steel plate by the combustion flame thermal oxidation process. Microscopic analyses revealed that the whiskers have some defects such as stacking faults and dislocations and also that manganese is the dominant impurity. An electron source with a single crystalline magnetite whisker with <110> orientation was fabricated using a micro-sampling instrument in a FIB system.