TEM thin films were cut from the middle part of the
transverse cross-section of the ECA pressed rods and prepared
using a twin jet technique in a solution of perchloric
acid (5%) and methanol (95%) at −50 ◦C and 25V for 60 s.
The electron microscope used was a Philips CM200 operating
at 200 keV. The microstructural parameters, such as the
lamellar spacing and the cell size were measured from the
bright field images.