Ph.D. thesis (pdf) - dirac

A.6. Other samples 201
NH 2
temperature is 0.999 g/cm 3 .
The sample used is from Sigma-Aldrich and it was twice distilled before usage.
The glass transition temperature at atmospheric pressure is T g = 187 K (for τ α = 100
s) and the isobaric fragility based on dielectric spectra is reported to be m P =
82 ± 3 [Mandanici et al., 2005; Alba-Simionesco et al., 1999]. (There has been some
controversy about the dielectric relaxation in m-toluidine, see reference [Mandanici
et al., 2005] and references therein.)
Pressure dependence of the alpha relaxation is reported in section 5.2.2 of this work.
We find x = 2.3 and a ratio of m P /m ρ = 1.2. The slope of the glass transition line
is dT g /dP = 0.085 K.MPa −1 .
Density data are available along four isotherms in the 278.4 K − 305.4 K range for
pressures up to 300 MPa [Würflinger, n.d.]. Tait fits and thermal expansivity in this
range were extrapolated by using the scheme described above for DBP in order to
determine density both as a function of temperature down to T g , and as a function
of pressure on the 216.4 K isotherm.
A.6 Other samples
In addition to the samples presented above, which have all been used in at least two
of the different studies in chapter 5 to 8 there are also a few samples which have
only been studied by time of flight at ambient pressure (chapter 8).
These samples where all acquired from Sigma-Aldrich.
Salol, T g =220 K, it is crystalline at ambient conditions so it was melted prior to
use. The sample did not recrystallize, which is easily verified from the absence of
O
Bragg peaks in measured neutron scattering data.
OH
O
Sorbitol T g =273 K is crystalline at ambient conditions it was melted prior to use.
The sample did not recrystallize, which is easily verified from the absence of Bragg