Tutorial Dielectric Application

This tutorial shows how to load a dielectric spectroscopy data file, inspect the available views, and create a simple Debye modes theory.

Load a dielectric data file

Start RepTate and create a new Dielectric application. Open the example file data/Dielectric_Spectroscopy/Debye.dls from the RepTate source tree.

Dielectric spectroscopy files use the .dls extension. A file should define the file parameters Mw and T and provide three data columns:

• w: angular frequency, in rad/s.

• e': elastic dielectric permittivity.

• e'': loss dielectric permittivity.

The file is loaded as a normal RepTate data set, so it can be selected in the data set tree, shown or hidden, and combined with theories and tools.

Inspect the views

Use the view selector to change how the data are displayed. The combined views log(e',e''(w)), semilog(e',e''(w)), and e',e''(w) plot both components against angular frequency. The single-component views show either e' or e'' only.

The Cole-Cole view plots e'' as a function of e'. This is useful for checking the shape of the dielectric response without using frequency as the horizontal axis.

The logarithmic views use base-10 logarithms, so they require positive frequencies and positive dielectric values in the displayed columns.

Fit Debye modes

Select the loaded file, choose Debye modes in the theory selector, and click Create Selected Theory. The theory initializes a set of discrete Debye modes between the minimum positive frequency and the maximum frequency of the selected data.

Use the number-of-modes control in the theory toolbar to change the number of modes. The View modes button toggles the markers used to inspect and adjust the modes on the plot. Calculate evaluates the theory with the current parameters, while Minimize Error fits the adjustable parameters to the data.

The Debye modes theory is a single-file theory. If more than one active file is present in the current data set, RepTate applies the theory to the first active file.