The index of refraction of BaTiO 3 above T c

We have recently reported measurements of the optic index of refraction, n(T), of BaTiO3 for T>Tc and interpreted the data in terms of dynamic islands of polarization. Here we show that the identical results are obtained in melt grown crystals; the original results were found in flux grown crystals (“butterflys”). These results give a quantitative measure of the square of a polarization above Tc.