NEUTRON DIFFRACTION STUDY OF Y 2 (Fe 1-x Si x ) 14 B

The outstanding permanent magnetic material Nd 2 Fe 14 B possesses very high energy product. But its Curie temperature is a little bit too low for practical application. Some elements were added into the material in order to raise the Curie temperature. Reference [9] and our recent experimental results show that the Curie temperature can be made higher by partiy subsituting silicon for iron in the material and in Y 2 Fe 14 B. For understanding the effect of silicon on magnetism, the occupancy of Si in Y 2 Fe 14 B was studied by neutron diffraction. The neutron diffraction results show that silicon occupies preferentially the sites of c, j 1 , and k 2 . The magnetic interaction theory is applied to explain the experimental results.