(A) Schematic cross section of the NSFCC. Two large (green) arrows drawn through the neutron windows and sample substrate indicate the path of a neutron beam. The outer cylinder, the lid at the bottom, and the slider are constructed with 304 stainless steel. (B) Picture of the NSFCC installed on the mirror sample stage where a view port (left side) and an incident neutron window (right side) are visible.
A block diagram of the hydraulic force system. The force system is composed of a ram assembly, an accumulator assembly and a pump assembly as delimited by the dashed straight lines. Hydraulic pressure propagates from the pump to the swivel head of the ram, as indicated by a long arrow drawn below the hydraulic tubing, while the nitrogen gas in the accumulator maintains an ultrastable hydraulic pressure. The stroke distance of the ram is 1.5 cm. In our design the head moves only 1 cm to compress a sample. The details of our confinement cell, circled by a dashed line, are shown in Fig. 1. The inset at the bottom provides a key for the symbols used in the diagram.
Scattering geometry for specular neutron reflection. The wave vector transfer , where and are the incident and reflected wave vectors, respectively.
An illustration of our thin-film sample architecture. In this experiment, we vary the gap separation by applying an external force against the quartz substrates.
(A) Neutron reflectivity data (symbols) at different hydraulic pressures applied and their model fits (solid line) using (B) the SLD profiles. For clarity, the data and the fits are vertically downshifted as pressure increases and the sublayers are labeled along the largest SLD profile only corresponding to the 300 psi data fit [the line at the top in (B)]. With increasing pressure, the width of the periodic fringes increases as noted by a pair of dashed lines, indicative of a decreasing gap separation between the quartz substrates. This decrease is also clearly observed in the SLD profiles (B). The reduced chi-square, , shown in (A) represents the goodness of each fit.
The plots of gap separation vs applied force. The dashed line is a linear fit for the points from the model fitting calculation with the last point excluded.
Gap separations at various pressures (and forces) applied.
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