Abstracts Book - IMRC 2018

• SC2-O027
Co7Sb2O12 SPINEL LIKE SOLID SOLUTIONS AS NEW VARISTOR
MATERIAL
Carolina Tabasco Novelo 1 , Isidro Gonzalez Panzo 2 , Fidel Fernando Gamboa Perera 1 , Ulises
Salazar Kuri 3 , Geonel Rodríguez Gattorno 1 , Patricia Quintana Owen 1
1
CINVESTAV-Mérida, Applied Physics, Mexico. 2 Benemerita Universidad Autonoma de Puebla,
CIDS-ICUAP, Mexico. 3 Benemerita Universidad Autonoma de Puebla, Physics Institute, Mexico.
Since the first ceramic varistor, SiC, was known it has been paid much attention
in the development of new metal oxide based varistors with an outstanding nonlinear
characteristic. Among the varistor systems suggested in the literature the
ZnO and SnO2 based varistors showed the highest non-linearity coefficient α.
ZnO ceramic varistors are multiphase system constituted by ZnO grains and
secondary phases as spinel (Zn7Sb2O12), pyrochlore (Zn2Bi3Sb3O4) and bismuth
oxide polymorphs as consequence of the large amount of dopant added to
modify its electrical response. On the other hand, SnO2 ceramics are single
phase ceramics with no formation of secondary phase despite the use of a
similar doping system with ZnO. M7Sb2O12 (M = Zn, Ni or Co) has been a widely
studied system due to its potential application as ceramic varistor or
thermistor and as potential magnetic storage material. The spinel properties
depend upon the nature of the ions A and B, their charge, and distribution
between tetrahedral and octahedral sites. In the present work, we have
explored the study of the effect of lithium doping on the structural and electrical
properties of Co7Sb2O12 spinel. A solid solution with formula general Li3xCo7-
4xSb2+xO12 and iso-structural with Co7Sb2O12 was found in the binary system
Co7Sb2O12-LiCoSbO4. The Co7Sb2O12 solid solutions were prepared by the
traditional ceramic processing and pressed (1 ton) into pellets of 7.2 mm
diameter and and
where V10 and V1 are the corresponding voltages at currents values of 10 and 1
mA, respectively. High non-linear electrical properties with a high breakdown
field were found for Co7Sb2O12 solid solution in the range 0.4 ≤ x ≤ 0.7, the α