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Lead-free piezoelectric ð1 ¡ xÞ½BNT ¡ BKT ¡ KNN ¡ xBCTZ ceramics with x content from 0 to 0.1 step 0.02 were prepared via the solid-state combustion technique. The effect of x concentration on the phase evolution, microstructure and electrical properties was methodically investigated. The XRD result of 0 x 0:04 showed a tetragonal phase. The coexistence phase between the rhombohedral and the tetragonal structure was observed at x 0:06 : The phase structure at a composition between 0.08 and 0.1 was dominated by a higher rhombohedral phase. The ceramics grain exhibited a cubic shape and the average grain size decreased from 1.15 to 0.83 mm with an increase in x content from 0 to 0.1. The temperature of e FA and e SA of the ceramics tended to decrease with increasing x concentration. The MPB composition was suggested at x around 0.06 where this ceramic exhibited its highest dielectric constant ðe SA D 2971Þ ; good ferroelectric properties ðP r » 20:83 mC/cm 2 and E c » 13:74 kV/cm) and excellent piezoelectric constant ðd 33 D 237 pC=NÞ :

A novel combustion technique has been developed to synthesize La 0.92 Mg 0.18 Fe 0.90 O 3 or LMF ceramics. The NH 2 CH 2 COOH was used as the fuel to accelerate the chemical reaction of raw materials. Thermogravimetric TG and differential thermal analysis DTA were used to estimate the calcination temperature in the range from 800 to 1000 • C. The pure perovskite phase was obtained for the samples calcined at 900 • C for 2 h. This calcination temperature was selected for the pellets sintered between 1000 • C and 1200 • C for 2 h. The effect of calcination and sintering temperatures on the phase and morphology evolution of perovskite LMF was investigated. The XRD patterns indicated that LMF exhibited orthorhombic perovskite structure. With increasing the firing temperatures, the lattice parameters and the unit cell volume changed only slightly; the average particle size and the average grain size tended to increase from 133 to 227 nm and 0.40 to 0.92 μm, respectively. The density of sintered ceramics changed between 3.19 and 3.37 g/cm 3 depending on the sintering temperature.