A furnace for coherent beam transmission topography applied to ferroelectric crystals

We describe a small furnace for transmission diffraction imaging studies, designed to (i) go up to 800 °C while having a temperature gradient as reduced as possible on a platelet-shaped insulating sample, (ii) allow a large and homogeneous beam to be transmitted/diffracted and (iii) preserve the coherence properties of these transmitted and diffracted beams, which are recorded at variable crystal-to-detector distances (typically 2-200 cm). We report experiments, to test the temperature gradient, on the ferroelectric to paraelectric transition of BaTi0 3 , and to check the preservation of the coherence properties of the beam, which include the observation of ferroelectric domains in a poled LiNbO 3 crystal.