Magnetic properties of cementite powder produced by reaction milling

Cementite powder obtained by reaction milling of elemental iron and graphite powder in a dual-drive planetary mill is used to study its magnetic property. The effect of milling and subsequent annealing of the cementite powder on its magnetic property is studied by using a vibrating sample magnetometer and Mossbauer spectroscopy. The coercive force, the specific saturation magnetization, and the Curie temperature are measured. These values depend on the phase composition obtained by milling and subsequent annealing. It has been found that after milling the saturation magnetization decreases and the coercivity increases. With annealing, coercivity initially increases and then decreases with increase in annealing temperature; where as saturation magnetization only increases in the same range. (C) 2008 Elsevier B.V. All rights reserved.