Dependence of optical and dielectric properties on heat treatment of calcium-doped manganites Mahrous R. Ahmed, E. Kh. Shokr, I. A. Abdel-Latif, Ibrahim Y. Khaled, E. M. M. Ibrahim and Sara A. Mohamed Eur. Phys. J. B, 97 8 (2024) 114 Published online: 07 August 2024 DOI: 10.1140/epjb/s10051-024-00741-0