Dy3+ and Sm3+ ratio variation effects on electrical properties of lithium fluoride bismuth borate glass system

Abstract

Since less attention was paid to study of electric properties of glasses doped with RE ions, in present work conductivity (AC and DC) and dielectric properties of Dysprosium (Dy3+) and Samarium (Sm3+) ion co-doped 60B2O3•30LiF•10Bi2O3 glasses were examined. Conventional melt quench method was used to synthesize the amorphous glass samples. It was observed that dc conductivity obeyed the Arrhenius law and the ac conductivity followed Jonscher's Power Law. The Conductivity mechanism was investigated on the basis of the trend followed by frequency exponent “s” parameter and all the compositions satisfied the Overlapping large polaron tunnelling (OLPT) model. Dielectric properties: Dielectric Constant (ε′), Dielectric loss (ε'′) and tangent loss (tanδ) were also investigated and observed to decrease with frequency and finally attained a minimum constant value at higher frequencies. The high rate of change in dielectric properties at low frequencies was attributed to space charge polarization while at higher frequencies it was decreased due to inertia of ions. Cole-Cole plots encompasses depressed semicircular arcs which evidenced the presence of constant phase element and non-Debye relaxation behaviour.