4. Conclusions
For samples substituted with 2% ions concentration:
1)
The average grain size is increased with increasing the ionic radii of the substituted ions.
2)
The defect concentration is increased at grain boundaries with increasing the ionic radii of substituted ions. The exception for Sm ferrite sample is due to the formation of SmO2 inside the bulk.
3)
For V-Li-sample the increase of I2 relative to the Nb sample is attributed to the smaller grain size.
4)
I1 is mostly decreased with increasing the ionic radii of substituted ions due to the dominated effect of intragranular porosity except for Sm–Li sample.
5)
The electrical resistivity is increased with increasing the ionic radii due to the increase of the intergranular porosity.
6)
The initial permeability is increased with the ionic radii due to the decrease of intragranular porosity and the increase of G.S. except for Gd-sample. The intragranular pores for Gd-sample are concentrated at the walls of the domains.