Structure, electric properties and positron annihilation studies of CuZnFe2O4 doped with BaTiO3 O. M. Hemeda, K. R. Mahmoud and T. Sharshar Eur. Phys. J. Plus, 129 8 (2014) 173 Published online: 18 August 2014 DOI: 10.1140/epjp/i2014-14173-4