Phase Transitions in the Brominated Ferroelectric Tris‐Sarcosine Calcium Chloride
paraelectrics SrTiO 3 and KTaO 3 . [ 9 ] However, the ultra-weak nature of the dipole moment in TSCC referred to below may reduce the effects of such long-range dipole interactions to a narrow temperature region around the critical point. This would mean that more conventional classical or quantum critical behaviour would be expected over a wider range of temperatures and tuning parameters. TSCC is hydrogen bonded and was characterized in the past as order-disorder albeit with no direct supporting evidence. [ 16,17 ] Since the time of these studies TSCC has come to be a prototypical displacive ferroelectrics, [ 18 ] as demonstrated by the existence of an under-damped soft mode. This mode can be followed into the GHz frequency regime [ 19 ] from highT values of ca 630 GHz = 21 cm −1 . Deuteration [ 20 ] produces little change in T C , implying that the transition is not controlled by the N-Cl-hydrogen bonds, a result compatible with the soft-mode mechanism operating in TSCC. [ 2 ]
Influence of epitaxial strain on elastocaloric effect in ferroelectric thin films
We report the influence of epitaxial strain um on the elastocaloric properties of BaTiO3 thin films.
Using thermodynamic calculations, we show that there exists a critical compressive stress r3c at
which the elastocaloric effect is maximized for any compressive misfit strain we investigate.
Moreover, it is found that jr3cj decreases significantly with decreasing jumj, which is accompanied
by a reduction of the elastocaloric response. Interestingly, a several fold enhancement in the
electrocaloric effect can be achieved for stress in proximity of r3c. The elastocaloric effect
predicted here may find potential cooling applications by combining the stress-mediated electrocaloric
effect or designing hybrid elastocaloric/electrocaloric devices in the future.
On the validity of area-based income measures to proxy household income
BackgroundThis paper assesses the agreement between household-level income data and an area-based income measure, and whether or not discrepancies create meaningful differences when applied in regression equations estimating total household prescription drug expenditures.MethodsUsing administrative data files for the population of BC, Canada, we calculate income deciles from both area-based census data and Canada Revenue Agency validated household-level data. These deciles are then compared for misclassification. Spearman's correlation, kappa coefficients and weighted kappa coefficients are all calculated. We then assess the validity of using the area-based income measure as a proxy for household income in regression equations explaining socio-economic inequalities in total prescription drug expenditures.ResultsThe variability between household-level income and area-based income is large. Only 37% of households are classified by area-based measures to be within one decile of the classification based on household-level incomes. Statistical evidence of the disagreement between income measures also indicates substantial misclassification, with Spearman's correlations, kappa coefficients and weighted kappa coefficients all indicating little agreement. The regression results show that the size of the coefficients changes considerably when area-based measures are used instead of household-level measures, and that use of area-based measures smooths out important variation across the income distribution.ConclusionThese results suggest that, in some contexts, the choice of area-based versus household-level income can drive conclusions in an important way. Access to reliable household-level income/socio-economic data such as the tax-validated data used in this study would unambiguously improve health research and therefore the evidence on which health and social policy would ideally rest.