Ion sweeping in conducting dielectric materials

Conductivity-related low-frequency dielectric losses frequently obscure loss peaks arising from dipole relaxations in dielectric materials. The application of moderately large electrical fields to ion containing liquids and solids in combination with temperature cycling enables one to reduce the contribution of conductivity to dielectric loss spectra significantly. Details of this electrical cleaning method are given. Its application is demonstrated and discussed for a diverse array of materials ranging from polymeric and small-molecule supercooled liquids to hydrated proteins and ice-like crystals. The suppression of conductivity-related losses allows one to gain insights into the low-frequency dynamics of such materials. The mobility of the ionic impurities at the base temperature and at the 'cleaning' temperature are briefly discussed.