Low temperature molten-salt synthesis of nanocrystalline cubic Sr2SbMnO6

Sr₂SbMnO₆ (SSM) powders were successfully synthesized at reasonably low temperatures via molten-salt synthesis (MSS) method using eutectic composition of 0.635 Li₂SO₄-0.365 Na₂SO₄ (flux). High-temperature cubic phase SSM was stabilized at room temperature by calcining the as-synthesized powders at 900 °C/10 h. The phase formation and morphology of these powders were characterized via X-ray powder diffraction and scanning electron microscopy, respectively. The SSM phase formation associated with ∼60 nm sized crystallites was also confirmed by transmission electron microscopy. The activation energy associated with the particle growth was found to be 95±5 kJ mol⁻¹. The dielectric constant of the tetragonal phase of the ceramic (fabricated using this cubic phase powder) with and without the flux (sulphates) has been monitored as a function of frequency (100 Hz-1 MHz) at room temperature. Internal barrier layer capacitance (IBLC) model was invoked to rationalize the dielectric properties.