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

Graphical abstract Highlights • Single phased α-(Fe 2 O 3) 1−X (Cr 2 O 3) X nanoparticles were prepared. • Band gap of Fe 2 O 3 is narrowed to 1.6 eV with addition of Cr. • Pectin was used as a gelling agent for Sol-gel synthesis. • Nanoparticles stabilised in corundum structure with R-3C space group. • Weak ferromagnetism was observed for the prepares α-(Fe 2 O 3) 1−X (Cr 2 O 3) X (0 ≤ x ≤ 1). Abstract We report on the tunable band engineering in α-(Fe 2 O 3) 1−X (Cr 2 O 3) 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-Fe 2 O 3 nanoparticles, doping of Cr 2 O 3 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-Fe 2 O 3 nanoparticles and illustrates that these nanoparticles have potential candidate in spintronic, optoelectronic, solar cell and photocatalysis applications. [ABSTRACT FROM AUTHOR]