Vol.:(0123456789) 1 3 Applied Physics A (2021) 127:526 https://doi.org/10.1007/s00339-021-04686-4 Infuence of samarium doping on structural, elastic, magnetic, dielectric, and electrical properties of nanocrystalline cobalt ferrite Mohd. Hashim 1  · Nehru Boda 2  · Ateeq Ahmed 3  · S. K. Sharma 4  · D. Ravinder 2  · Edapalli Sumalatha 2  · Anwar Ul‑Hamid 5  · Mukhlis M. Ismail 6  · Mohd. Chaman 7  · Sagar E. Shirsath 8  · Ravi Kumar 9  · Shalendra Kumar 10,11  · Sher Singh Meena 12  · Mohammad Nasir 13 Received: 6 April 2021 / Accepted: 9 June 2021 / Published online: 15 June 2021 © The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature 2021 Abstract Samarium-doped cobalt ferrite nanoparticles CoSm x Fe 2-x O 4 (0 ≤ x ≤ 0.1) were synthesized using citrate gel auto-combustion method, followed by annealing at 500 °C for 4 h in air. The physical properties of the samples were evaluated using x-ray difraction, Fourier transform infrared spectroscopy, transmission electron microscopy, Mössbauer, magnetic, and dielectric measurement techniques. Rietveld analysis of XRD data confrmed the formation of a single-phase cubic spinel structure for all compositions. Experimental results indicated that doping with samarium (Sm) strongly afected the magnetic proper- ties of CoSm x Fe 2-x O 4 nanoparticles. The values of saturation magnetization (M S ) were reduced from 62.99 (x = 0) to 41.17 (x = 0.1) emu/g. Room-temperature Mössbauer spectra show two sextets (tetrahedral and octahedral sites), and the values of the hyperfne magnetic feld (H hf ) of both sextets are found to decrease with Sm-doping. The values of the isomer shift show that all Fe-ions are found in the Fe 3+ state. The interstitial Sm ions positioned within CoFe 2 O 4 realized a dielectric constant dispersion that displayed a maximum at low frequency. With an increase in samarium ion concentration, the two dielectric relaxations reached a very wide range of frequencies. This can be attributed to the contribution of conduction in the grains and grain boundaries of ferrite. Samples with samarium contents of 0.01 and 0.03 showed high impedance stability at 50 and 150 °C, respectively, rendering them suitable for use as a high-frequency window below 1 kHz. Keywords Co-Sm nanoferrites · Dielectric dispersion · Frequency window * Mohd. Hashim md.hashim09@gmail.com * Ateeq Ahmed ateeqamu124@gmail.com * D. Ravinder ravindergupta28@redifmail.com * Sher Singh Meena ssingh@barc.gov.in 1 Department of Applied Physics, Aligarh Muslim University, Aligarh 202002, India 2 Department of Physics, Osmania University, Hyderabad, India 3 Department of Materials Science and Engineering, Chosun University, Gwangju 61452, Republic of Korea 4 Nan Chand Anglo Sanskrit College of Meerut, Meerut, India 5 Center for Engineering Research, Research Institute, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia 6 Department of Applied Sciences, University of Technology, Baghdad, Iraq 7 Mewat Engineering College, Nuh, Haryana 122107, India 8 School of Materials Science and Engineering, University of New South Wales, Sydney NSW2052, Australia 9 Department of Physics, National Institute of Technology, Hamirpur, H P 177 005, India 10 Department of Physics, College of Science, King Faisal University, P.O. Box 400, Al-Ahsa 31982, Saudi Arabia 11 Department of Physics, School of Engineering, University of Petroleum & Energy Studies, Dehradun 248007, India 12 Solid State Physics Division, Bhabha Atomic Research Center, Mumbai 400 085, India 13 Department of Materials Science Engineering, Dankkok University, Cheonan 31116, Republic of Korea