Relaxor or classical ferroelectric behavior in A-site substituted perovskite type Ba1−x(Sm0.5Na0.5)xTiO3

New ferroelectric ceramics of ABO3 perovskite type were synthetized in the Ba1−x(Sm0.5Na0.5)xTiO3 system by solid state reaction technique. The effect of the replacement of barium by samarium and sodium in the A cationic site on structural and physical properties was investigated. These compounds crystallize with tetragonal or cubic symmetry. The material is classical ferroelectric for 0⩽x⩽0.10⩽x⩽0.1 and x⩾0.5x⩾0.5, and present a relaxor behavior for 0.2⩽x<0.40.2⩽x<0.4. The dielectric behavior depends upon the cationic disorder in the A-site and the cell size. Small rate substitution allows a ferroelectric–paraelectric transition. For higher rate of substitution the possible random position of the Sm–Na cations brings to a relaxor state and when the substitution rate x becomes higher than 0.5, the material comes back to a ferroelectric state due to the reduced cell size. Some of these new compositions are of interest for applications due to their physical properties and environmentally friendly character.

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