Hi. Im having trouble finding sources to the information that i am seeking (sometimes you find really good phyisics/chemistry books through google). Nm particles of iron 100 nm has the same melting point as iron in bulk. Is there any chemistry books online that shows why even small particles of iron must be heated up to 1500C in order to produce iron-rich spheres?. iron-rich spheres can only be produced by a very high temperature of 1500C even if the particles are very small, as i understand it. As i understand it, it is impossible to get iron-rich spheres from just heating metals with low temperatures of 500C... So what i am looking for is some good sources or websites that explains all this, i am offcourse interested in hearing your comments also. Thanks for the help in advance.