Improved electrical properties of lead-free neodymium doped Ba0.85Ca0.15Zr0.1Ti0.9O3 piezoceramics

Lead-free Ba(0.85-x)NdxCa0.15Zr0.1Ti0.9O3 (x = 0.000, 0.005, 0.010, 0.015, 0.020, and 0.025 mol%) ceramics were prepared following conventional solid state reaction route. Dielectric, ferroelectric and piezoelectric properties of the ceramics sintered at 1400 degrees C were studied. All the samples were found to be the relaxors with diffusivity lying in the range 1.58 <= gamma <= 1.77. gamma increases with increasing x. The spontaneous polarization (P-s) increases to the maximum value of 8.65 mu C/cm(2) for x = 0.010, before it decreases with further increase in x. The remnant polarization (P-r), which is similar to 4.2 mu C/cm(2) for the undoped sample, increases with x to 4.8 mu C/cm(2) corresponding to x = 0.010 and then decreases with increasing x. The coercive field (E-c) follows the opposite trend, showing a minimum of 2.052 kV/cm at x = 0.010. The piezoelectric charge coefficient (d(33)) and electromechanical coupling factor (k(p)) peak at the high values of 275 pC/N and 0.36 respectively for the ceramics having the optimum Nd content of x = 0.010.