Abstract:
The varistor ZnO has been made by using raw materials: ZnO
(E-Merck) and additive 0 %, 2.5 %, 5%, 7.5%, and 10% wt.
Bi2O3. The important property of varistor ZnO is coefficient of
non linier () and it can give influence correlation between
current I and voltage V. The mixing process of raw materials
was done by using magnetic stirrer and liquid acetone as
media, and then was dried at 60oC, and also grinded until
passing 400 meshes. Pellet was made by using pressing 50
MPa, and fired at 1050oC with holding time 2 hours. After
firing, all samples are characterized, such as: measurement of
coefficient of non linier (), and observation of microstructure
by using Scanning Electron Microscope (SEM). The results
show that sample without additive has less than 5 and this
sample has not properties as varistor, but the highest value of
is 64 for sample with additive 7.5% Bi2O3. The result of
photos SEM shows that the increase of percentage of additive
Bi2O3 can influence of formation grain boundary and grain
size. Where, value of coefficient of non linier () is depend on
existing of grain boundary and thickness of grain boundary.
