Study of structural, optical, electrical, and multiferroic properties of Cu ions doped NdFeO3 nanomaterials

Pure and Cu-doped NdFeO 3 nanoparticles were synthesized using the sol-gel citrate method and systematically investigated for their structural, optical, magnetic, dielectric, and ferroelectric properties. X-ray diffraction confirmed an orthorhombic perovskite structure ( Pbnm ), with a minor CuO impurity in the doped sample. Cu substitution reduced the crystallite size and slightly increased the lattice parameters. Optical studies revealed a decrease in band gap from 2.70 to 2.59 eV. Magnetic measurements showed enhanced remnant and maximum magnetization upon Cu doping. Dielectric analysis indicated frequency-dependent behaviour with low dielectric loss (< 1), while AC conductivity increased at higher frequencies. Notably, Cu doping led to a substantial enhancement in ferroelectric polarization, with the maximum polarization increasing from 1.45 to 13.82 µC/cm 2 at ± 4 kV/cm, demonstrating improved multiferroic performance.