Vol.:(0123456789) 1 3 Applied Physics A (2021) 127:903 https://doi.org/10.1007/s00339-021-05040-4 The efect of silicon on cerium zirconates pyrochlores nanoparticles Saleem Mumtaz 1  · Muhammad Naeem Ashiq 1  · Bashir Ahmad 1  · Muhammad Faheem Ashiq 1  · Ruqiya Sehrish Gohar 1  · Nosheen Nazar 1  · Shams H. Abdel‑Hafez 2  · Wael A. El‑Sayed 3  · Hafz Muhammad Tahir Farid 4 Received: 9 August 2021 / Accepted: 20 October 2021 / Published online: 11 November 2021 © The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature 2021 Abstract Disordered pyrochlores Ce 2 Zr 2-x Si x O 7 (x = 0.0, 0.25, 0.50, and 0.75) with appropriate compositions have been manufac- tured by normal micro-emulsion method and the efects of Si doping on dielectric and electrical properties were observed. The as-synthesized materials were analyzed via various techniques including X-ray difraction (XRD), Fourier transforms infrared (FTIR) spectroscopy, X-ray fuorescence (XRF) spectroscopy, Scanning electron microscopy (SEM), the temper- ature-dependent electrical capacity, and the frequency-dependent dielectric measurements. The XRD results revealed that the synthesized pyrochlores were single phased except x = 0 with crystallite size ranging from 18 to 30 nm. SEM analysis showed that particles were homogenous and well distributed. The resistivity of material frst increased and then decreased showing metal to semiconducting transition. A decrease in dielectric properties with the increase in frequency was observed owing to natural magnetic resonance phenomenon. The dielectric and electrical measurements were enhanced by doping of Si contents which revealed that the prepared material is suitable for frequency flters, oscillators, and resonators. Keywords Nanoparticles · Pyrochlores · Dielectric parameters · Electrical resistivity 1 Introduction Pyrochlore, a group of materials having common formula A 2 B 2 O 7 (where "A 3+ " is trivalent and "B 4+ " is tetravalent cation) have gotten signifcant attention of the scientists due to various remarkable chemical and physical properties like ferroelectric, nuclear waste immobilization, catalytic, dielec- tric, and piezoelectric parameters [1–3]. These materials contain high ionic conductivity i.e., suit- able for electrolytes and have mixed conductivity of elec- trodes for solid oxide fuel cells [4]. In addition, these materi- als also possessed good thermal and chemical stability. The actual formula of pyrochlore is A 2 B 2 O 6 O' because of the two crystallographic non-equivalent sites for the oxide ions. Usu- ally, cation "A" has ionic radius in the range of 0.9–1.2 Å with the coordination number of 8, whereas the smaller cation “B” has the ionic radius in the range of 0.5–0.75 Å and a coordination number 6 [5, 6]. Pyrochlore structures have an extensive range of uses in the felds of radioactive waste management, semiconducting materials, catalysis, and high primitive dielectric materials [7]. Similarly, these materials have also been used as elec- trodes in the solid oxide fuel cells (SOFC), gas sensors in gas sensing devices, frequency-dependent electronic devices like resonators, frequency flters, oscillators, and energy storage capacitor [8, 9]. The efect of Si metal as dopant in the pyrochlore increases the conductivity of the synthesized materials and is also fruitful for applications in integrated devices [10, 11]. Sven et al. [ 12] synthesized pure Ce 2 Zr 2 O 7 and k- Ce 2 Zr 2 O 8 by sol-gel method and used in the catalysis feld. Similarly, J.Lian et al. [13] prepared La 2 Zr 2 O 7- Ce 2 Zr 2 O 7 materials via reduction route and investigate its properties and suggest that it was used in absorption of radiation from nuclear fuel. K. Popa et al. [14] produced cerium zirconates * Hafz Muhammad Tahir Farid tahirfaridbzu@gmail.com 1 Institute of Chemical Sciences, Bahauddin Zakaryia University, Multan 6100, Pakistan 2 Department of Chemistry, College of Science, Taif University, P.O.Box 11099, Taif 21944, Saudi Arabia 3 Department of Chemistry, College of Science, Qassim University, Buraidah, Saudi Arabia 4 Department of Physics, Bahauddin Zakariya University, Multan 60800, Pakistan