The effect of nonmagnetic Zn impurities on the structural parameters and effective magnetic moment of electron-doped superconducting cuprates Eu2−xCexCu1−yZnyO4+α−δ (ECCZO) with x = 0.10 and 0.15 and y = 0 and 0.01 has been investigated using XRD and SQUID measurements. From XRD measurements, it is found that the lattice parameter of c and the Cu-O bond length increase with increasing y. The crystallite size of ECCZO samples was relatively smaller than the sample without impurities determined by the Debye–Scherrer equation and the W-H Plot method. Changes in the lattice parameters of c and Cu-O bond length can affect the appearance of superconductivity (Tc). The smaller the value of the lattice parameter of c and the Cu-O bond length causes the distance between the conducting layer and the charge reservoir to be close enough so that the charge transfer process becomes easier. From the magnetic susceptibility measurement, paramagnetic characteristics were observed for samples with x = 0.10. Meanwhile, for samples with x = 0.15, diamagnetic characteristics can be identified in sample with y = 0. The onset of Tc was observed around 11 K, as indicated by a change from paramagnetic to diamagnetic characteristics. The superconductivity phase disappears with y = 0.01. The effective magnetic moments in samples with y = 0 are smaller than those in samples with y = 0.01. The effective magnetic moment in ECCZO can be contributed by Cu2+. When the amount of Cu2+ decreases due to the addition of nonmagnetic Zn2+ atoms, the overall effective magnetic moment value also decreases. Another possibility that causes a decrease in the value of the magnetic moment of the ECCZO is the existence of stripe-pinning model, which results in suppressed superconductivity by Zn.
Mixed valence manganite materials have been studied due to their interesting physical properties such as their magnetoresistance (MR) effect. The change of Mn3+/Mn4+ ratio affects the possible bonds between anion and cation and their spin structure that may occur in the samples. The aim of this research is to study the change of magnetoresistance effect and magnetic properties of La0.67Sr0.33MnO3 (LSMO) by doping the Mn site with Ni ion. La0.67Sr0.33Mn1-xNixO3 samples were synthesized by using sol-gel method and characterized by using X-ray diffractometer (XRD) and Energy Dispersive X-ray spectroscopy (EDX) to confirm whether Ni has been doped successfully to the parental compound or not. XRD results showed that the samples have a single phase and Ni peak has been detected in the EDX result of Ni-doped LSMO. Resistivity and magnetic measurement showed that LSMO material has ferromagnetic metallic behavior, while x = 0.20 Ni-doped LSMO sample showed paramagnetic insulator behavior. The absolute value of the MR for un-doped sample is higher than the doped sample when the low field is applied, while under the influence of the high magnetic field, it become smaller than the doped sample.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.