Abstract
Hematite is an n-type semiconductor, and its semiconducting properties can
further be improved by nano-structuring and doping. In several optoelectronic devices,
such as thermoelectric and solar cells, both n- and p-type semiconductors are required.
The p-type hematite can be synthesized by doping cations, such as Ni2+, Mg2+, Cu2+, and
Mn2+. Furthermore, hematite is a weak ferromagnetic material, and its magnetic
properties vary with the size of nanoparticles, doping of cations as well as doping
concentration. This chapter discusses various properties of nanostructured nickel-doped
hematite. As nickel is a ferromagnetic divalent dopant with a high magnetic moment,
its doping in hematite together with nano-structuring shows a large variation in both
electrical and magnetic properties in nickel.