Effect Of X (X = Al3+, V3+, Sc3+, In3+ And Y3+) Doping On The Dielectric Properties Of Lead-Free Bzt Ceramics

Al3+-, V3+-, Sc3+-, In3+- and Y3+-ion-doped lead-free X-BaZr0.15Ti0.85O3(X-BZT-15) ceramics were prepared with the solid-phase reaction method. The crystal structure, micromorphology, and dielectric properties of the X-BZT-15 ceramics were studied. X-ray diffractometry shows that the prepared ceramics have a perovskite structure. Raman spectroscopy shows that the doped ions of BZT-15 ceramics do not significantly change the vibration frequency of the A(1)(LO3) mode, but have a greater impact on the new A(1g) mode. The unit cell volume first increases and then decreases as the ion radius increases. When the doped ion radius is less than 0.0885 nm (Sc3+), the substitution type of the doped cation is B-substitution. When the doping ion radius is greater than 0.0885 nm (Sc3+), the substitution type of the doped cations gradually changes from B-site substitution to A-site substitution. Electron scanning microscopy shows that the doping of Y3+ and V3+ can promote grain growth, and the doping of Sc3+ can refine the grains. The doping of Y3+ can promote polarization, the doping of V3+ can passivate the grain boundaries, and the doping of both ions can promote the improvement of dielectric properties. The diffuseness of the phase transition shows that as the ionic radius increases, the c value increases. The doped ions are Sc3+, and the maximum value of c is 1.877. Then c decreases as the ion radius increases.