Study of the colossal dielectric response in LaFe1−xZnxO3−δ perovskites Refka Andoulsi-Fezei, Karima Horchani-Naifer and Mokhtar Férid Eur. Phys. J. Plus, 136 7 (2021) 791 Published online: 31 July 2021 DOI: 10.1140/epjp/s13360-021-01776-3