Interferometric Study of the Microtopography Arising out of 90° Domain Walls in Single Crystals of Barium Titanate

The surface structure caused by 90° domain walls on barium titanate crystals in the ferroelectric tetragonal state has been studied as a function of temperature employing optical and interferometric techniques. It has been shown that the c-domain surfaces are inclined against the a domains at an angle tan−1 (c−a)/a. The observed stepladder structure of alternating `a' and `c' domains shows head-to-tail coupling of the dipoles. Special cases of 90° wall configuration with head-to-head or tail-to-tail orientation have also been observed.