Dielectric properties and scaling behavior of lithium tungsten phosphate glasses

Abstract

In the present study a series of ternary (30 Li 2 O, (70-x) P 2 O 5 , xWO3) glasses were prepared and their dielectric properties and ac conductivity were investigated. The measurements have been taken in the frequency range from 100 Hz to 100 kHz and over the temperature range from 296 K to 578 K. The temperature dependence of ac conductivity can be adequately explained by considering the contributions from mixed ionic and electronic mechanisms. In the studied glasses it is found that the ac conductivity increases with increasing frequency. By investigating the relation between temperature and the frequency exponent "s" of the power law σ ac 0Aω s , it is found that the Correlated Barrier Hopping model (CBH) is appropriate for describing the conduction mechanism in the samples. In an attempt to investigate the universality of ac conductivity in these glasses, it is found that the data obtained follow Rolling scaling model. When considering the dielectric properties, it is found that the M″vs. M′ plots give master ColeCole curves at all temperatures. These results can be considered as an indication of the presence of space charge or accumulation of charges in some regions inside the samples. The relation between M″/ M max″ and f/f p represent a master plot at different temperatures. These scaling suggest the existence of a distribution of potential wells, in which the carriers are trapped.

IMPACT OF CuO CONTENT ON THE DIELECTRIC PROPERTIES OF ZINC SODIUM PHOSPHATE GLASSES CONTAINING Al2O3

“…composition diversity, good chemical durability (especially when some metallic ions are introduced into their networks), and low-cost starting materials as well as their various applications [1]. On the other hand, phosphate glasses have lower glass transition temperature, higher thermal expansion coefficient and higher transmission in the UV region compared with silicate and borate glasses [2]. It is known that, phosphate glasses represent a dielectric energy-storage material, and therefore, they are useful for fabricating high energy density devices [3].The addition of transition metal oxides, such as Fe2O3, to phosphate glasses makes them more chemical resistive due to the replacing of the easily hydrated P-O-P bonds by the stronger Fe-O-P ones [4].…”