FIG 5 - uploaded by Germano Iannacchione
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Scaling plot of A (δCp at T = TAC ), obtain from fitting the excess specific heat of the SmA-SmC phase transition to Eq. (10), against ρS. The solid line has a slope of −0.5 while the dashed line a slope of −0.56.
Source publication
A high-resolution calorimetric study has been carried out on nano-colloidal dispersions of aerosils in the liquid crystal 4-n-pentylphenylthiol-4'-n-octyloxybenzoate (¯ 8S5) as a function of aerosil concentration and temperature spanning the smectic-C to nematic phases. Over this temperature range, this liquid crystal possesses two continuous XY ph...
Contexts in source publication
Context 1
... LC, it is not clear how robust is this result. The fit coeffi- cient A of Eq. (10) appears to smoothly decrease with increasing ρ S . This is consistent with the behavior of the SmA-SmC transition of 7O.4 in hydrophobic aerosil [13]. The parameter A is also a measure of the tricritical na- ture of the SmA-SmC transition. A log-log plot shown in Fig. 5 of A versus ρ S reveals a power-law scaling given by A ∝ ρ −0.5 S ...
Context 2
... qual- ity fits were made using an extended Landau form that found the upper stability temperature increasing with ρ S consistent with the shift of the observed transition. In addition, the coefficient A, representing the heat ca- pacity maximum at the SmA-SmC transition, exhibits a scaling with the aerosil conjugate density as A ∝ ρ −0.5 S , see Fig. 5. It is clear that this transition, while evolv- ing in a systematic fashion, remains mean-field over the entire range of ρ S studied. This may be a reflection of the SmA-SmC transition behaving as if it were at its up- per critical dimension moderating the effect of the QRD produced by the aerosil ...
