Characterization of Solid‐State Reaction of Barium Carbonate and Titanium Dioxide by Spatially Resolved Electron Energy Loss Spectroscopy

A mixture of ultrafine submicrometer‐sized BaCO 3 powder and TiO 2 (rutile) powder was calcined in air at 700°C, 800°C, and 900°C, and then quenched to liquid nitrogen temperature in each case. The cross‐sectional quenched specimens were characterized by spatially resolved electron energy‐loss spectroscopy ( SR ‐ EELS ). The energy‐loss near‐edge structures ( ELNES ) were sequentially extracted at 1.3 to 5.3 nm in width from SR ‐ EELS image obtained from the rectangularly cut SR ‐ EELS slit aperture put on the synthesized BaTiO 3 layer and TiO 2 rutile powder. The ELNES of Ti‐L 2,3 edges and Ba‐M 4,5 edges clearly show fine structure changes from the surface of BaTiO 3 layer to the TiO 2 bulk region reflected from crystallinity of synthesized BaTiO 3 , lattice distortion of TiO 2 caused by Ba diffusion, and lattice misfit between BaTiO 3 and TiO 2 without formation of Ba 2 TiO 4 and other titanate phases.