Effects of Annealing on the Structure and Distribution of Charge States of Iron Implanted into (Alpha)-Al2O3 at 77 K.

摘要

Implantation of iron into (alpha)-Al(sub 2)O(sub 3) at 77 K produces an amorphous state for fluences greater than about 3 (times) 10(sup 16) Fe/cm(sup 2). Iron in the as-implanted (amorphous) specimens is distributed among two Fe(sup 2+), two Fe(sup 4+), and the Fe(sup 0) states. The conversion electron Moessbauer (CEMS) spectra for a sample containing 7 (times) 10(sup 16) Fe/cm(sup 2) show all iron to be converted to Fe(sup 3+) after annealing in oxygen for 1 h at 700(degree)C and above. The transmission electron microscopy (TEM) shows the structure to be mostly Y-Al(sub 2)O(sub 3) after the 900(degree)C anneal and all (alpha)-Al(sub 2)O(sub 3) after the 1100(degree)C anneal. 5 refs., 4 figs., 1 tab.