Structural and dielectric properties of copper-based spinel ferrites Hafiz Muhammad Tahir Farid, Ishtiaq Ahmad, Irshad Ali, Asif Mahmood and Shahid M. Ramay Eur. Phys. J. Plus, 133 2 (2018) 41 Published online: 08 February 2018 DOI: 10.1140/epjp/i2018-11832-4