On the ratio of Curie--Weiss constants in ferroelectrics undergoing second order phase transitions

Abstract

Scaling hypothesis is used to construct the equations of state that provide the experimentally observed variety of the Curie--Weiss constants ratios (i.e., the ratios of the slopes between the temperature dependencies of inverse of susceptibility below and above the critical point) in uniaxial ferroelectrics. The results are exemplified by the TGS crystal and by the methylammonium salts MAPCB and MAPBB.

Keywords:

• Critical exponents
• Electric susceptibility
• Critical amplitudes
• Curie--Weiss constants
• Biasing field
• Scaling invariants

Acknowledgement

This work was supported by the Committee for Scientific Research (Poland); project register number 3 T09A 023 26.