Morphology of large α-Fe precipitate formed inside sapphire by ion implantation and annealing

The morphology of large α-Fe precipitate in sapphire has been studied by transmission electron microscopy. The particles greater than 20 nm clearly have faceted outlines. Two typical outlines have been observed. One outline consists of two hexagons on {0001}, two parallelograms on {112¯0} and four parallelograms on {21¯1¯3} of sapphire. The other outline consists of two hexagons on {0001}, two irregular hexagons on {112¯0}, four parallelograms on {21¯1¯3} and four parallelograms on {21¯1¯9¯} of sapphire. Sapphire plays the role of receptacles and characterizes the shape of the large α-Fe particles.