Sensitivity of electrical behaviours of ZnO nanoparticle–Bi₂O₃–Mn₂O₃ varistor system to various La₂O₃ doping compositions

Figures & data

Figure 1. XRD patterns of ZnO nanoparticles–Bi₂O₃–Mn₂O₃ varistor ceramics doped with: 0.0, 1.0, 2.0 and 3.0 mol% La₂O₃.

Figure 2. Typical SEM micrographs of ZnO nanoparticles–Bi₂O₃–Mn₂O₃ varistor ceramics doped with various amounts of La₂O₃ additive: (a) 0.0 mol% La₂O₃, (b) 1.0 mol% La₂O₃, (c) 2.0 mol% La₂O₃ and (d) 3.0 mol% La₂O₃.

Table 1. Influence of La₂O₃ on average grain size, current–voltage (V–I) and capacitance–voltage (C–V) characteristic parameters of ZnO nanoparticles–Bi₂O₃–Mn₂O₃ varistor.

Doping amount of La2O3 (mol%)	Grain size (µm)	Vb (V/mm)	α	IL (mA/cm^2)	Nd (cm^−3) (×10^20)	NIS (cm^−2 eV^−1) (×10^12)	ΦB (eV)	ω (nm)
0.0	29.3	2614.8	43	0.473	1.3	3.2	3.9	8.6
1.0	19.6	3349.5	66	0.214	2.1	2.2	7.3	3.9
2.0	15.2	4264.2	50	0.310	1.1	4.5	5.7	7.7
3.0	8.5	5730.7	35	0.596	0.3	9.7	3.2	11.2

Figure 3. The C–V characteristics of ZnO nanoparticles–Bi₂O₃–Mn₂O₃ varistor ceramics doped with: 0.0, 1.0, 2.0 and 3.0 mol% La₂O₃.

Figure 4. The C–V behaviour parameters include: (a) donor densities and barrier heights and (b) interfacial states density and depletion layer of ZnO nanoparticles–Bi₂O₃–Mn₂O₃ varistor ceramics doped with: 0.0, 1.0, 2.0 and 3.0 mol% La₂O₃.

Figure 5. (a) The Voltage–Current characteristic, and (b) the variation of breakdown voltage and average grain size of ZnO nanoparticles–Bi₂O₃–Mn₂O₃ varistor ceramics doped with: 0.0, 1.0, 2.0 and 3.0 mol% La₂O₃.

Figure 6. The variation of nonlinear coefficient and leakage current of ZnO nanoparticles–Bi₂O₃–Mn₂O₃ varistor with: 0.0, 1.0, 2.0 and 3.0 mol% La₂O₃.

Figure 7. Variation of the (a) Frequency and (b) Capacitance of ZnO nanoparticles–Bi₂O₃–Mn₂O₃ varistor as a function of the different amounts of: 0.0, 1.0, 2.0 and 3.0 mol% La₂O₃.