Linking Curie constant and phase transition temperature with fundamental ion properties

ABSTRACT

The Curie Law and Curie – Weiss Law, empirically determined relations, with experimentally determined Curie constant(s) and Curie temperature(s), T_c, are related, through correlation, to the permittivity. The Clausius – Mossotti relation, a fundamental equation that links: permittivity; index of refraction through the Lorentz – Lorenz equation; and, conductivity through Maxwell's formula; is here shown to incorporate both the ferroelectric Curie Law and Curie – Weiss Law. In light of recent developments with regard to coordination and temperature dependent ion properties, radii and polarizabilities, of Perovskites, it is now possible to model and design temperature dependent properties: lattice parameters and volumes; permittivity; as well as the temperature of polarization induced structural phase transitions; of at least Perovskites through the Clausius – Mossotti equation using fundamental ion properties which also form the foundational basis upon which the indices of refraction, through the Lorentz – Lorenz equation, and, conductivity, through Maxwell's formula, depend.

KEYWORDS:

• Curie constant
• Curie temperature
• Clausius-Mossotti relation
• permittivity
• phase transition temperature
• lattice parameter
• thermal expansion coefficient
• Perovskite crystal lattice modeling
• temperature dependent parameters
• ionic radii
• ionic polarizability