Magnetic and optical properties of Fe doped crednerite CuMnO2
A geometrically frustrated magnetic CuMnO2 system has been investigated because of its rich magnetic properties. Neutron diffraction, synchrotron X-ray, magnetic, X-ray photoemission spectroscopy (XPS) and UV-Visible spectroscopy measurements have been carried out on CuMnO2 and 5% Fe doped CuMnO2 samples. Fe doping reduces the distortion. Moreover, Fe doping induces the ferromagnetic coupling between ab planes. The value of magnetization is increased with Fe doping but coercivity is decreased. These might be due to the direct Mn–Mn exchange and Mn–O–Cu–O–Mn super–super exchange interactions. The UV-Vis data indicate the appearance of new energy bands in these compounds. The XPS study indicates that Fe is in the 3+ state.