COEFFICIENTS OF THERMAL-EXPANSION FOR BARIUM HEXAFERRITE

The thermal expansion coefficients along the a axis (alpha(a)) and c a xis (alpha(c)) of barium hexaferrite were measured from room temperatu re to 850 degrees C. The thermal expansion of barium hexaferrite along the a axis and c axis was found to be linear as a function of tempera ture, indicating constant thermal expansion coefficients over this tem perature range. The specific values for alpha(c) and alpha(a) were cal culated to be 12.2+/-0.9 and 9.99+/-1.1 ppm/degrees C, respectively. T he measurements were performed using a standard x-ray powder diffracti on setup equipped with a high temperature stage. (C) 1996 American Ins titute of Physics.