{HEAD ~ Each particle} is covered with an insulative oxide film which contains 0.3 to 0.8% of {TAIL ~ oxygen} by weight based on the particle 
{ HEAD ~ Each particle } is covered with an insulative oxide film which contains 0.3 to 0.8 % of { TAIL ~ oxygen } by weight based on the particle
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH