Ferromagnetism in lead graphite-pencils and magnetic composite with CoFe2O4 particles

This work has been initiated with a curiosity to investigate the elemental composition and magnetic response of different grades of lead pencils (6B, 2B, HB, 2H, 5H) that people use in daily life. Interestingly, experimental results landed with a great achievement of observing soft magnetism in lead pencils, indicating a wide scope of magnetic tuning for room temperature applications. A novel magnetic composite has been synthesized by mixing different concentration of CoFe2O4 (CF) nanoparticles in 5H and 6B pencils for studying the magnetic tailoring aspects using pencils. Our results showed different possibilities of controlling disorder induced ferromagnetic parameters and a simple approach of producing sufficiently high coercive magnetic composite using pencils. (C) 2011 Elsevier Ltd. All rights reserved.