Microstructure of BST. What is the tail?

[vinven7]

Attached is the SEM microstructure of Barium strontium Titanate (BST) to which has been added over 2% borate so as to increase the grain size. The image clearly shows abnormal grain growth and the grains are huge - around a 100 um. But also visible in the image are these tails that emanate from the grains. Does anyone have any guess as to what that is?

 

[streeters]

i may be wrong, but are the tails growing along scratches? could that be a preferential growth path?

 

[vinven7]

that may be true. Thanks for the info.