Weak ferromagnetism in band-gap engineered α-(Fe2O3)1−X(Cr2O3)X nanoparticles

We report on the tunable band engineering in α-(Fe₂O₃)_1−X(Cr₂O₃)_X nanoparticles. Nanoparticles were prepared by the sol-gel method and stabilised in the hexagonal crystal structure with R-3C space group. At room temperature band-gap studies have shown the narrowing of the band gap from 2.1 eV to 1.6 eV with Cr addition. Compared to antiferromagnetic α-Fe₂O₃ nanoparticles, doping of Cr₂O₃ increases the magnetic hysteresis significantly. Impedance spectroscopic studies have revealed Maxwell-Wagner dielectric relaxation near room temperature. Our results improve the understanding of the structural, optical, dielectric and magnetic properties of Cr-doped α-Fe₂O₃ nanoparticles and illustrates that these nanoparticles have potential candidate in spintronic, optoelectronic, solar cell and photocatalysis applications.