Transmission electron micrograph (freeze etched) of the surface of a crystal of Barium Titanate (BaTiO3) after being etched in HCI at 0 degrees Centigrade. At this temperature, Barium Titanate has an orthorhombic crystal structure. The rough and smooth areas indicate domains in which the polaraizations are parallel but in opposite directions. Magnification: x6500. The distance between the two black circles in the upper right margin is 10 microns.