Cr doping effects on the structural and magnetic properties of BiFeO3 nanoparticles synthesized hydrothermal method

Abstract

Chromium-doped multiferroic bismuth ferrite BiFe1-xCrxO3 (x = 0.0, 0.05, 0.10, 0.15, 0.20) nanoparticles were synthesized by the conventional hydrothermal method. The effects of Cr doping on the structural and magnetic properties of BiFeO3 nanoparticles were investigated at room temperature using X-ray diffraction (XRD), X-ray absorption fine structure (XAFS) spectroscopy and superconducting quantum interference device (SQUID). From the scanning electron microscope (SEM) images, the morphology of BiFeO3 nanoparticles was effected obviously by Cr doping, though the actual doping concentrations were below 4% according to the inductively coupled plasma mass spectrometry (ICP-MS) results. The XRD results showed that all samples had rhombohedral R3c crystal structure without any impurity phase, and further confirmed by the Bi L3-edge and Fe K-edge XAFS spectra. However, the Cr K-edge XAFS results of the doped samples revealed the presence of the oxides related Cr as the doping concentration increase. Furthermore, different Cr-doped concentrations played an important role on the magnetic enhancement of BiFeO3, and the abnormal performance of magnetism might be attributed to the unexpected oxides.