The Almax Plate DAC is an innovative diamond anvil cell based on the novel design of Prof. Reinhard Boehler at the Max Planck Institute in Mainz, Germany. With the advent of conical diamond anvils described in the paper by R. Boehler et al., High Press. Res. 24, 391 (2004), comes the possibility of having diamond anvil cells with very large conical apertures without the drawback of obstructing materials for the incoming of outgoing beams.

In the Almax Plate DAC two kinematically-mounted steel plates are elastically deflected with the use of a driving gearbox. Based on the lever principle, the symmetrical deflection of the plates, although very small, is enough to bring into near-contact the diamond anvils and hence generate the required pressures in the sample space.

The conical anvils are supported by tungsten carbide seats, which provides several benefits. Firstly, it circumvents the need for beryllium plates as support for the diamond anvils. The net result is the avoidance of the usual halo coming the diffraction pattern of Be. Secondly, the mechanical resistance of tungsten carbide, being higher than that of beryllium, provides backing seats with longer lifetime. Thirdly, by having tungsten carbide backing plates it is possible to use the cell at high temperatures. Of particular interest then is the use of the Boehler-Almax Plate DAC in combination with a laser heating set-up by also taking advantage of its large conical access.

The Almax Plate DAC is very easy to handle and align. It makes use of distinctive tilt-adjustment screws and a special gear box. Diamond anvils cannot be accidentally broken because they are only brought into contact by applying the high force necessary to bend the plates.

The gearbox required to deflect the plates is made of three high-strength, high-precision spur gears which uniformly rotate the three matching clamping screws. These, in turn, act as levers. The conical aperture along the axis of the diamond anvil cell is 85°, whereas the Almax PlateDAC flat design offers a horizontal aperture (in the plane of the gasket) of more than 80° on 3 sectors, offering a near-panoramic view. The vertical opening is above 20°.

The Almax Plate DAC can be supplied with the usual selection of diamonds, type Ia Raman-selected for low- or ultra-low fluorescence or type IIas, with conical apertures of 85° degrees on both sides of the cell. The total height of the cell is around 21 mm for an external diameter of 49 mm.

The gasket is held in place by a convenient gasket holder, in a similar fashion to other Diacell® diamond anvil cells. Gasket materials such as steel, Inconel, beryllium copper alloy, rhenium, as well as pure beryllium (contact us for details) can be supplied with this cell.

This video shows how easy it is to align this cell.

A gas membrane adaptor kit is available for the Plate DAC.  A video animation of this gas membrane upgrading kit can be seen here. A Huber goniometer head is also available for this gas membrane adaptor as well.

Applications

The Almax Plate DAC is particularly well suited for X-Ray experiments as it enables diffraction measurements with high transmission factor and very low background.  Indeed, the absence of Be plates, which are replaced by large aperture tungsten carbide seats, combined with the fact that the conical anvils are nearly 15% thinner than the standard designs, considerably enhances the X-ray transmission. The large apertures on both side also makes the cell singularly suited for use with laser heating (particularly double-sided heating) set-ups.