A 2-Theta-Resolved Hadox Study Of Batio3 Linz Crystals

X-ray intensities in reciprocal-lattice space can be measured with high resolution in two dimensions by improved high-angle double-crystal X-ray diffractometry (HADOX). The method has been applied to the cubic-to-tetragonal phase transition in BaTiO3 Linz crystals grown by the method of top-seeded solution growth; the results are compared with those of previous experiments on butterfly crystals of BaTiO3. It is found that the two types of crystals behave in quantitatively different manners around the transition: the transition temperature, the temperature range of two-phase coexistence etc. are different. In both types of crystals, on the other hand, the lattice constant of the cubic phase shows a different temperature dependence when the tetragonal phase coexists, and the orientation of crystal grains shows anomalous behaviour. The results are discussed in terms of the effect of stresses.