Effect of Y3+ doping of rare earth element on microstructure and antiferromagnetism of CuFeO2 ceramics

Abstract

In this work, a set of CuFe1-xYxO2 (x = 0–0.02) specimens were synthesized using the conventional high-temperature solid-state reaction method, and the impact of Y3+ doping on the microstructure and magnetic properties of CuFeO2 ceramics was investigated. The introduction of Y3+ ions in place of Fe3+ ions induced alterations in the microstructure of CuFeO2, leading to lattice distortion. X-ray diffraction analysis confirmed the presence of impurity phases in the CuFe1-xYxO2 series samples at high doping concentrations (x ≥ 0.015). In contrast, low doping concentrations (x ≤ 0.0125) exhibited a singular copper-iron ore structure. The microstructures of the ceramic samples were examined using SEM, findings suggest that the presence of high concentrations of dopants hinders the formation of ceramic samples with high density. XPS analysis reveals that the introduction of a low concentration of Y3+ dopant does not impact the oxidation state of Cu and Fe. Raman spectroscopy results indicate that the doping process weakens the vibration mode of CuFe1-xYxO2 ceramic samples. Additionally, measurements conducted using the PPMS demonstrate that the serial samples undergo two consecutive magnetic phase transitions at temperatures of 16K and 11K. The magnetization versus M − H curve of the doped sample exhibits both antiferromagnetic and ferromagnetic behavior. The increase in magnetic susceptibility can be attributed to the greater magnetic moment of doped Y3+ compared to Fe3+. Consequently, the magnetic transformation of the sample is influenced by various factors, including lattice distortion, alterations in ion valence states, variations in microscopic defect types, and modifications in magnetic interactions.