REACTION DIFFUSION IN THE Y_2O_3-Fe_2O_3 SYSTEM

摘要

Solid state reactions in the Y_2O_3-Fe_2O_3 system were studied by means of different types of diffusion couples. Simultaneous growth of the YfeO_3 and Y_3Fe_5O_12 ternary phases was observed on Y_2O_3-Fe_2O_3 couples, whereas only the YfeO_3 phase grows on Y_2O_3-Y_3Fe_5O_12 and Y_2O_3-gas-Fe_2O_3couples. The growth rates were determined by layer thickness measurements on couples reacted at 1220, 1300 and 1352 deg C in air and at 1304 deg C in oxygen for times ranging from 8 to 256 h. The growth kinetics is parabolic in all cases.