Ferroelectricity in barium sodium tantalate Ba2NaTa5O15

Ceramic samples of the mixed system Ba 2 NaNb 5(1- x ) Ta 5 x O 15 were investigated through dielectric measurements. Ferroelectric activity was confirmed through observation of the 50 Hz D - E hysteresis loop for samples with x ≧0.4. As a result, the end member, barium sodium tantalate (Ba 2 NaTa 5 O 15 ), was assigned as a new ferroelectric below the 40 K range.