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ZnO/Sm (0, 2, and 4 at.%) nanopowders have been prepared by using chemical refluxing method and characterized to understand their chemical, structural, optical, as well as magnetic properties. Energy dispersive X-ray analysis (EDAX) spectra confirmed the existence of zinc, samarium, and oxygen in the prepared samples with expected ratios. X-ray diffraction (XRD) studies indicate that the Sm has been successfully incorporated in the ZnO host matrix. The average diameter of the particles confirmed by transmission electron microscopy (TEM) studies was in the range 14–20 nm. X-ray photoelectron spectroscopy (XPS) analysis divulged that the Sm ions existed in trivalent (+ 3) state in the doped ZnO lattice. Magnetic measurements showed that the undoped ZnO was diamagnetic and the Sm-doped ZnO nanopowders were paramagnetic at 300 K. The paramagnetic nature of the doped samples may be attributed to the random distribution of the Sm 3+ ions in ZnO lattice, giving rise to the formation of a weak interaction.

The present study describes the elemental and structural as well as the room temperature magnetic properties of pure ZnS, Zn0.96Eu0.04S, and Zn0.95Eu0.04Tb0.01S NPs. The energy dispersive X-ray spectroscopy (EDAX) perceived the existence of zinc, terbium, europium, and sulfur in the prepared samples in expected stoichiometry ratio. X-ray diffraction (XRD) studies revealed that all the prepared NPs had a cubic structure. Transmission electron microscopy (TEM) studies showed the creation of wispy particles with an average size in the range of 5–8 nm. Magnetization (M) versus applied magnetic field (H) studies indicated that the pure ZnS NPs exhibited diamagnetic behavior, whereas both Zn0.96Eu0.04S and Zn0.95Eu0.04Tb0.01S NPs evinced the ferromagnetic nature at room temperature. However, suppression in ferromagnetism was observed in Zn0.95Eu0.04Tb0.01S compared to Zn0.96Eu0.04S nanoparticles due to the interactions between the Eu–Eu ions, Tb–Tb ions, and Eu–Tb ions. The above experimental results suggesting that both doped and co-doped ZnS nanoparticles are useful for spintronic device applications.