Piston-cylinder cell

As with neutron powder methods, both monochromatic and time-of-flight (Laue) techniques have been used for single-crystal neutron studies. Such studies are much less numerous, however, as a result of the difficulty of compressing suitably sized (>1 mm ) single-crystal sample to the required pressure while maintaining the crystal quality. The piston cylinder cell design of Me Whan and others [128] has been used at the ILL reactor source for a number of neutron structural studies to... 

A conventional Raman instrument is suitable for high-pressure Raman measurements. The pressure device can be a piston-cylinder cell or a DAC. The first Raman studies with a piston-cylinder cell were made in 1957 (6). 

The sample is mounted in a small cylinder containing a fluid, and the cylinder is, in turn, mounted in a piston cylinder cell. Load is applied to the piston until the desired pressure is reached inside the cell. The piston is then clamped with a locking nut. The advantage of the piston cylinder device is that it may break but not explode since a liquid does not expand dramatically. The drawback is that changing the pressure requires dismounting the cell to load it again. Steel or copper-beryllium clamps can be used for neutron structure studies since they allow almost three-dimensional studies. Clamps capable of higher pressures are made with an alumina... 

A flow system has been designed to pump fluid through the flow cell. A piston-cylinder arrangement is used as a pump-like" device by... 

Crystallization of ECSCs was isothermally carried out under high pressure using a piston cylinder high pressure cell with diamond window (PCDW) originally made by us. The formation of isolated ECSCs was confirmed by means of transmission electron microscopy (TEM). 

Figure 10.3 Schematic illustration of a piston-cylinder type arrangement of the diamond anvil cell. The sample is contained in a hole drilled in the gasket.

Both of these in situ devices use substantially less solution (volumes of solution samples for each kinetic run are usually of the order of a few cm3) than a typical piston-cylinder apparatus. The pill-box cell method has the advantage that the cell can be filled in an appropriate glove box for oxygen-sensitive samples or for nonaqueous solvent-based systems that are sensitive to moisture. Temperature control is exerted by fluid circulating through the metal block. 

A streaming current detector based on a completely different principle than the above instruments is presented in [299], The dispersion is in a narrow space between a vertical cylindrical vessel and a coaxial piston, which moves back and forth along the axis. The potential between two gold electrodes on the wall of the cylinder at different heights is measured, and its zero value is identified with the IEP. The apparatus own response corresponds to the electrokinetic behavior of the piston and cell materials. In the presence of a colloid, the piston and the cell are assumed to be covered with colloidal particles. The above design has been utilized in some commercial instruments ... 

Fig. 4.41 A schematic drawing of a piston-cylinder high-pressure cell using a modified diamond anvil. (Reprinted with permission from J. Macromol. Sci. 1992, 7, 91, by courtesy of Marcel Dekker Inc.)...

An original route is that proposed by Ter-Minassian and Million in 1983 [44] with their pneumatic compensation calorimeter, represented in Fig 10. The tubular sample cell 4 is in good thermal contact with four metallic bulbs. Two of them operate like bulb 1 in the figure, Le. as pneumatic thermal detectors. They are filled with gas, say around 1 bar, and their pressure is compared, by means of a differential manometer, with the constant pressure of a reference reservoir 3 immersed in the surrounding thermostat block 5. Therefore, they detect any temperature change of the sample. The two oflier bulbs operate like bulb 2, i.e. as pneumatic energy-compensating devices. They are also filled with gas, say around 1 bar, but they are connected to flie piston-cylinder 7 which enables the heat of compression (or decompression) necessary to cancel the temperature difference between the sample and thermostat (as detected with the first set of bulbs) to be produced in the bulb. More recently, Zimmermaim and Keller built a comparable pneumatic compensation calorimeter whose calorimetric performances were carefully examined [45]. 

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