Evaluation of rare earth oxides doping SnO2.(Co1/4,Mn3/4)O-based varistor system

Abstract

The present paper aims to verify the inuence of rare earth oxide such as lanthanum (La2O3) and neodymium (Nd2O3) doping SnO2 + 0.25%CoO + 0.75%MnO2 + 0.05%Ta2O5 system. The analysis focus on microstructural inuence on electrical properties. Microstructural analysis were made by using Transmission Electron Microscopy (TEM) at different regions of the samples. From such analysis it was found that La2O3 and Nd2O3 oxides cause heterogeneous segregation and precipitation at grain boundary concerning cobalt and manganese, decreasing the nonohmic electrical properties, as discussed, likely due to the increasing of grain boundary non-active potential barriers

Enhanced photocatalytic activity and ultra-sensitive benzaldehyde sensing performance of a SnO2·ZnO·TiO2 nanomaterial

“…Tin(IV) oxide can be doped with oxides of iron or manganese for excellent uses. 5,6 Zinc oxide nanoparticles have vast applications, such as in the ceramics industry, 7 medicine, 8 food additives, 9 and UV absorbers 10 and in nuclear reactors as a corrosion preventer. 11 A fascinating property of mixed metal oxides is their versatility; they can be used for many purposes with high efficiency.…”

Electrical barriers formation at the grain boundaries of Co-doped SnO2 varistor ceramics

“…It is believed that the vacancies are preferentially created at the surface of the SnO 2 grains, increasing oxygen diffusion at grain boundaries and then promoting densification. 7 Although multi-components system such as SnO 2 -CoONb 2 O 5 -Cr 2 O 3 lead apparently to single-phase ceramics, 1 in the binary system CoO-SnO 2 the solid solution limit seems very weak since polyphased ceramics are obtained. 6 The ionic radius mismatch between Co and Sn is very small (r Co 2+ = 0.074 nm, r Sn 4+ = 0.071 nm, r = 0.003 nm).…”

Study of the response behavior of a CdS–SnO2 thick film for high selectivity towards propanol gas

“…16 Doping with various compounds has been investigated (e.g., with CuO). 17 Doping with cobalt and manganese gives a material that can be used in high voltage, for example; in addition, tin(IV) oxide can be doped with the oxides of iron or manganese. 18 J. K. Srivastava et al 19 reported on the microstructural proprieties of the PbO-doped SnO 2 sensor for the detection of methanol, propanol, and acetone.…”