Coexistence of superparamagnetism and spin-glass like behavior in zinc-substituted cobalt ferrite nanoparticles
- PDF / 1,779,738 Bytes
- 11 Pages / 595.276 x 790.866 pts Page_size
- 98 Downloads / 170 Views
Coexistence of superparamagnetism and spin‑glass like behavior in zinc‑substituted cobalt ferrite nanoparticles Gassem M. Alzoubi1 · A. M. Alsmadi1,2 · G. A. Alna’washi1 · B. Salameh2 · M. Shatnawi1 · Sufian Alnemrat1 · B. A. Albiss3 · I. Bsoul4 Received: 1 April 2020 / Accepted: 18 May 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract We have performed a systematic study on the effect of Zn substitution on the structural and magnetic properties of crystalline zinc-substituted cobalt ferrite nanoparticles, Znx Co1−x Fe2 O4 with x = 0, 0.25, 0.5, 0.75, and 1, prepared by hydrothermal method. The structural and magnetic properties of these nanoparticles were investigated by XRD, TEM, FTIR, and VSM. All the ferrite nanoparticles were prepared with sizes smaller than 20 nm, thus lying within the range of single-domain regime. The results of Rietveld refinement revealed that all prepared nanoparticles were cubic and single phase, and the increase in Zn concentration resulted in an increase in the lattice constant, x-ray density, and the average bond length on tetrahedral sites. The TEM measurements showed that the nanoparticles were monodisperse and spherical in shape. All FTIR spectra of the prepared ferrites showed two dominant absorption bands, thus confirming the formation of single-phase spinel structure with two sub-lattices: tetrahedral (A-site) and octahedral (B-site). The room temperature M versus H magnetization measurements revealed that the ferrite nanoparticles were ferromagnetic for x = 0 and superparamagnetic for x ≥ 0.25 . At 10 K, all ferrite nanoparticles showed ferrimagnetic behavior that is weakened by Zn substitution. The saturation magnetization and the first anisotropy constant were observed to decrease with increasing Zn concentration. The zero field cooled and field cooled magnetization data revealed that both superparamagnetic and spin-glass like states may coexist together depending on amount of Zn concentration and temperature. Keywords Spinel ferrites · Rietveld refinement · Magnetization · Superparamagnetism · Spin-glass · LA model
1 Introduction Magnetic ferrites are a group of materials that contain iron oxide as a major constituent. They have been investigated intensively during the past few decades as they can be utilized in several applications such as permanent magnets, chemical sensors, high density recording systems, microwave devices, and biomedical applications [1–5]. * Gassem M. Alzoubi [email protected] 1
Department of Physics, The Hashemite University, Zarqa 13115, Jordan
2
Department of Physics, Kuwait University, 13060 Safat, Kuwait
3
Department of Physics, Jordan University of Science and Technology, Irbid 22110, Jordan
4
Department of Physics, Al al-Bayt University, Mafraq 13040, Jordan
Spinel ferrites, a class of magnetic ferrites, crystallize into a cubic spinel type structure with a space group Fd3m and have the general molecular formula AB2 O4 , where A2+ and B3+ are the divalent and trivalent cations, respectively [6]. The
Data Loading...
