Effect of annealing time on thermally stimulated current in kidney stone samples

Abstract

An electret is a dielectric material which retains the polarization produced in it for a longer time and produces the electrostatic field without any source of voltage. The biomaterials like collagen, DNA, RNA and blood vessel walls etc possess this property. The kidney stone mainly consists of calcium oxalate and calcium phosphate, which are dipolar in nature. The pellet of the powdered kidney stone was formed in a mica window and identical aluminium electrodes were prepared. The thermal polarization was carried out by sandwiching the sample between aluminium electrodes in electrode assembly, which was kept in digital controlled oven. The observed behaviour of thermally stimulated current (TSC) peak is found to be strongly dependent on annealing time, which shows the presence of shallow and deeper traps in material. These traps are probably formed during the crystallization of substance in kidney.