The high-Q static scattering of 3-methyl pyridine/D2O mixtures without and with antagonistic salt

Here we focus on the high-Q small-angle neutron scattering where we observed deviations from an ideal power law Q−2. From theory, this deviation Δ arises from the critical correlation-function exponent ηd in d dimensions. The investigated systems were 3-methyl pyridine/D2O without and with antagonistitc salt. They display the critical behavior of a 3d and 2d Ising system, respectively. In the first case, the value of Δ matches the ideal value η3 well, but in the latter case the value of Δ is affected by the two confined dimensions and the third dimension.