Comprehensive review on Froehlich entropy estimation: a technique to investigate the state of order in condensed matter

TL;DR

This paper reviews the use of Froehlich entropy estimation as a reliable method to assess the order and phase transition behavior in various condensed matter systems through dielectric measurements.

Contribution

It provides a comprehensive overview of how Froehlich entropy is applied across different materials to evaluate their state of order, highlighting its reliability and versatility.

Findings

Froehlich entropy correlates with material order and phase transitions.

The method is applicable to a wide range of materials including liquids, crystals, and nanoparticles.

Froehlich entropy estimation complements traditional experimental techniques.

Abstract

The so-called Froehlich entropy is the entropy variation of a material under the application of an electric field. This quantity can be calculated, under suitable hypotheses, directly from the measured real part of the dielectric function. Although Froehlich entropy is defined for a biased sample, a straightforward physical interpretation correlates it to the state of order of the considered physical system in absence of field. When Froehlich entropy is calculated from experimental results, its trend is able to give several information about the evolution in temperature of the explored compound, especially of its phase transition features. We here provide a comprehensive review of the physical systems (dipolar liquids and nematicons, organic molecular crystals, metallic nanoparticles, inorganic disordered ferroelectrics, etc.) where this approach has been exploited with the aim of evaluating their state of order. The variety of compounds where this method has been applied demonstrates that the estimation of the Froehlich entropy can be considered a trustworthy tool for carrying out study on the state of order of different classes of materials. Indeed Froehlich entropy evaluation can be considered a fruitful and reliable investigation technique which can be exploited alongside more usual experimental approaches.