Abstract
Ba
0.8
Sr
0.2
Zr
0.1
Ti
0.9
O
3
@MgO-Al
2
O
3
@ZnO-B
2
O
3
-SiO
2
(BSZT@MgO-Al
2
O
3
@ZBSO) core double-shell lead-free nanoceramic is prepared by facile protocol. The protocol involves three steps of (a) BSZT synthesis by co-precipitation, (b) coating of MgO-Al
2
O
3
layer through co-precipitation, and (c) ZBSO deposition via sol-precipitation method. The diameter of the resultant BSZT@MgO-Al
2
O
3
@ZBSO core double-shell nanoparticles is about 280 nm, and the average thicknesses of the MgO-Al
2
O
3
and ZBSO layers are about 8 and 13 nm, respectively. The physical and chemical properties of BSZT@MgO-Al
2
O
3
@ZBSO are tuned by varying the ratio between MgO and Al
2
O
3
of MgO-Al
2
O
3
layer. The results reveal that the grain size increases with the decrease in the MgO/Al
2
O
3
ratio, while the dielectric properties initially increase and then decrease with increase of Al
2
O
3
content. After sintering at 1150 °C for 2 h, the MgO-Al
2
O
3
in the interlayer self-assembled into a MgAl
2
O
4
spinel phase. Thus, fine-grained relaxor ferroelectric BSZT@MgAl
2
O
4
@ZBSO core double-shell ceramic nanoceramics (grain size ≤ 300 nm) were obtained. The lead-free core double-shell nanoparticles with Mg/Al ratio of 4:2 exhibit the maximum energy storage density of 0.91 J/cm
3
under a maximum polarization field of 28.08 kV/mm.
Graphical abstract
Enhanced energy storage was observed in the lead-free mixed oxide core double-shell barium strontium zirconate titanate@magnesium aluminate@zinc oxide-boron trioxide-silica nanoceramics.