Tamis Dudo1, Christopher P. Landee1, Juan Matos2, and Mark M. Turnbull1. (1) Clark University, Worcester, MA, (2) Insituto Venezolano de Investigaciones Cientificas, Caracas, Venezuela
Magnetism is a property conventionally associated with transition metals and transition metal complexes with unpaired d electrons. In one allotropic form, carbon exists as graphite, which is structurally highly regular and which contains no unpaired electrons. However, some structurally highly irregular allotropes of carbon, with surface areas in the thousands of square meters per milligram have been reported to display magnetic properties. We prepared the highly irregular networks of carbon by the pyrolysis of saccharose(from sugar cane) dissolved either in water or KOH aqueous solution, recrystallized, and then thermally stabilized. The resulting 2D or 3D random networks of carbon were then activated via treatment with CO2 at 800¢ªC or carbonized under N2 flow at 800¢ªC. The random nature of the carbon networks thus synthesized was confirmed by obtaining a Philips microscopy SEM image, and the presence of unpaired electrons was established via EPR spectroscopy. We then set out and performed a series of experiments using a Quantum Design MPMS-XL SQUID magnetometer, in which we experimentally measured the magnetization of the samples as function of applied field at certain fixed temperatures, ranging in magnitude from 1.8K to 325K. We also measured magnetization as a function of temperature, going from 1.8K to 325K. From our measurements we detected small moments in our samples, and concluded that our samples were paramagnetic at low temperatures (i.e 1.8K-10K) and diamagnetic from 10K to 325K.
Back to General Poster Session 1
Back to The 34th Northeast Regional Meeting (October 5-7 2006)