Logarithmic correction of the electric susceptibility in paraelectric tris-sarcosine calcium chloride

Abstract

The dielectric constant tris-sarcosine calcium chloride [${(\mathrm{C}{\mathrm{H}}_{3}\ensuremath{-}\mathrm{N}\mathrm{H}\ensuremath{-}\mathrm{C}{\mathrm{H}}_{2}\ensuremath{-}\mathrm{C}\mathrm{O}\mathrm{O}\mathrm{H})}_{3}$\ifmmode\cdot\else\textperiodcentered\fi{}Ca${\mathrm{Cl}}_{2}$] has been measured with a relative precision of \ensuremath{\sim}0.0005 from the transition temperature ${T}_{c}$ to ${T}_{c}+60$ K. Over more than 2 orders of magnitude of reduced temperature [$\frac{(T\ensuremath{-}{T}_{c})}{{T}_{c}}$], it follows accurately the logarithmically corrected mean-field behavior of uniaxial dipolar ferroelectrics. It is shown unambiguously that these corrections are superior to a power law. Close to ${T}_{c}$ ($T<{T}_{c}+0.3$ K), the dielectric constant becomes affected by roundoff effects. Previous results on tris-sarcosine calcium chloride are reviewed in the light of these new findings.