The Magnetic, Electrical and Optical Properties of Rare Earth Er 3+ Doped Lead Borate Glass

Owing to the unique electronic structure of rare earth elements, we address in this paper the magnetic, electrical and optical properties of a prepared lead borate glass of composition (mol.%) 70PbO·30B 2 O 3 . The glass is doped with different ErCl 3 contents. A vibrating-sample magnetometer was used to characterize the magnetic properties. Increasing the additive concentration led to an increase in the saturation magnetization without significant effects on the coercivity. Optical reflectance spectra of the doped glasses revealed the development of absorption bands as a result of Er 3+ intra-configurational ( f – f ) transitions. The calculated allowed direct energy gap was found to increase monotonically with increasing dopant concentration. The results of the ac conductivity showed a decrease in the activation energy values with increasing frequency and an increase in the ac conductivity values with increasing temperature, which mimics the semiconducting behavior. The incorporation of the rare earth ion (Er 3+ ) facilitated the electronic conduction due to the increase of the non-bridging oxygen units. Increasing the dopant concentration led also to the participation of the ionic conductions. However, further increase of ErCl 3 (above 1 mol.%) caused a decrease in the conductivity. Samples with dopant content up to 1 mol.% ErCl 3 are accompanied by a high dielectric constant value of about 40. It can be concluded that samples doped with 1 mol.% ErCl 3 or less can be used as energy storage material in electronic devices, whereas glass samples with higher dopant content can be used for magnetic applications.