Enhanced magnetic properties of Fe³⁺ doped ZnS nanocrystals via low temperature co-precipitation: spintronic and nano-device applications

Abstract

The present work emphasises synthesis and characterization of undoped and Fe3+ doped ZnS nanocrystals. The prepared samples are synthesized by simple co-precipitation technique. The recorded XRD pattern confirms the cubic structure of prepared samples and its estimated average crystallite size is 3–3.5 nm range, and also evaluated micro-structural parameters. SEM images of prepared samples exhibit granular structure with spherical particles and non uniform in shape, size where as Fe3+ doped sample is more agglomerated. TEM images of undoped sample depicted rod like structures where as Fe3+ doped sample exhibits spherical shaped structures. The energy bands obtained in UV–vis region from optical absorption spectrum are recognized as characterstic bands of Fe3+ ions and also evaluated the crystal field, inter electronic parameters (Dq, B and C). EPR spectrum of Fe3+ doped sample exhibited a strong signal at g = 2.136. Photoluminescence spectrum of undoped sample is witnessed by strong blue emission band at 421 nm where as Fe3+ doped ZnS has an additional weak peak observed at 609 nm (4T2 → 6A1). The evaluated CCT values are 2568 K for ZnS and 3079 K for Fe3+ doped ZnS. VSM analysis reveals the observation of enhanced magnetism for Fe3+ doped ZnS nanocrystals compared to undoped sample ZnS. Thermal analysis signifies that the prepared samples are stable upto 888 °C (ZnS) and 993 °C (Fe3+ doped ZnS). The prepared materials may suitable for the various device applications in nanoscale magnetic, optical-spintronic devices and led to fabricate DMS materials for new trending applications.

Photon and Phonon Coherence to Enhance Photoluminescence by Magnetic Polarons in Mn-Doped Rb3Cd2Cl7 Perovskites

“…The excitation spectrum in PLE is significantly red-shifted with Mn doping, which is related to the 275 nm band edge of Rb 3 Cd 2 Cl 7 and the formation of Mn–Mn pairs at the adjacent octahedral site. , When more Mn ions are doped into the lattice, especially when the feed ratio Mn/(Mn + Cd) is 10%, the largest red shift of the band edge in PLE reaches 320 nm. This is a typical character of the EMP, and ferromagnetism occurs in these TM ion-doped semiconductors. − This red shift is often caused by the coupling between FM Mn–Mn pairs and free excitons near the band edge. However, when the feed ratio further increases, the CT band gradually blue-shifts due to the appearance of AFM coupling between Mn pairs and the formation of an AFM polaron out of the free exciton interaction with the AFM order. ,, This phenomenon of the AFM polaron also exists in ZnO/Mn and ZnSnO 3 :Mn nanostructures. , Compared with other feed ratios, the 10% Mn-doped sample has very high luminous efficiency because the EMP unit in the lattice may be the most important excitation at this feed ratio and plays a dramatic role in the emission, though single Mn d–d transitions are still dominant in this compound.…”

Prediction of metastable energy level distribution of D3+ (D = Cr and Fe) doped phosphors based on machine learning

“…The dataset for Cr-doped samples is shown in Table 2, 43–71 and the dataset for Fe-doped samples is presented in Table 3. 72–96 These data, after preprocessing, serve as input features for the regression models listed in Section 2.3, enabling the prediction of Cr 3+ and Fe 3+ behavior in different environments.…”

Enhancement of the photocatalytic activity of fabricated ZnS nanoparticles in the photodegradation of methylene blue

“…The most important challenge in the performance of photocatalysis is the low rate of production and the high rate of the recombination of electron-hole pairs. The preferred crystalline phase, lattice structure, morphology, and the size of the fabricated ZnS NPs could extend the optical band gap upon the maximum absorption wavelength 350 nm to enhance the electro-optic and photocatalytic properties [29,30]. The rate of photodegradation and oxidizing reactivity have been improved by increasing the maximum absorption wavelength to the visible region i.e., red shifting the optical absorption edge from UV to the visible region [31].…”