Fabrication of a spin-polarized electron emitter with <110>-oriented magnetite whisker



<110>-oriented single crystal magnetite (Fe3O4) whiskers 30 to 300 nm in diameter were synthesized on a stainless steel plate by means of the combustion flame thermal oxidation process. An electron source with this single magnetite whisker was fabricated by using a micro-sampling instrument in an FIB system. The temperature dependence of the spin polarization of field-emitted electrons from this electron source was measured by using a Mott electron polarimeter. The spin polarization of this sample was found to be 15% at room temperature. This emitter is an oxidative resistance, and can be handled in the atmosphere. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)