Dielectric properties of Stycast 1266 over the 0.07-300 K temperature range

We used Stycast 1266 in a high-pressure, low-temperature transducer. In order to ascertain the dependence of capacitance and loss on temperature, we measured the temperature behaviour of the dielectric constant and the dissipation factor of Stycast 1266 at 1 KHz between 0.07 and 300 K. We found a smooth decrease of the dielectric constant with decreasing T. The temperature dependence below 1 K is well explained by the tunneling model. The loss tangent showed very low values (always less than 5 x 10(-5)), with a peak around 260 K that can be ascribed to dielectric relaxation processes. (C) 2000 Elsevier Science Ltd. All rights reserved.