D-DIA geometry allows operating in 6/6 or 6/8 modes (number of first stage anvils/number of cubes). At ID06-LVP, all parts are machined by users or ID06-LVP members themselves.  Users are welcome to provide all assembly parts/cubes.

Cubes

The second-stage anvils or cubes are characterized by a truncated edge length (2.5 - 5, 7, 8, 11, 17 mm), an edge length (14, 26, 32 mm) and material (Tungsten carbide, Cubic boron nitride, Sintered diamond). Availability of each type and length should be checked with C. Wilson. 6/8 mode is used for a hydrostatic sample compression in a 2-stage mode. Typical experiments using this setup include chemical synthesis, phase diagram investigations, etc. The assembly must be prepared outside the press and introduced in one piece, aligned and compressed to run. Instructions for preparing an assembly for 6/8 mode are presented below. Any deviation, if your way of assembling is different, is possible!

Four cubes should have pyrophyllite gaskets glued on. They all are made in-house on pyrophyllite furnished by Ceramic Substrates that is delivered in plates of specified thickness according to eventual use. They are then machined on our desktop milling machines, which is particularly cost-effective and ensures rapid production.

Use UHU/Tombow stick glue (no superglue!). The way gaskets should be glued is shown in Fig.1. There are 6 short and 6 long gaskets. Gasket dimensions are specific for each assembly size (consult with your LC about that). It is important to glue the gaskets as precisely as possible!  If the thickness of gaskets varies more then 0,02 micron it is highly recommended to grind the gaskets using a sandpaper.

   

   

Figure 1. Instruction for proper alingment of the pyrophyllite gaskets.

All cubes are recommended to be covered with adhesive tape. Those that don't have gaskets on requiring the tape to be removed from the truncated corner in a way that it is enough space left for a gasket (Fig. 2). Remove tape along the x-ray beam.

Afterwards, Balsa wood pieces must be glued (use super glue!) on cubes with gaskets (3 for each side with a gasket). Make sure there is no wood along the x-ray beam. The thickness of these pieces must be close to the height of gaskets.

   

   

Figure 2. Instruction for using adhesive tape and alingmend of Balsa wood pieces.

The assembly order of the cubes for typical 2-stage 6/8 mode is shown below. X-ray transparent gaskets/windows can be made from epoxy diamond, MgO, Boron epoxy (consult with your LC for that).

 

Figure 3. Instruction for the assembly of the cubes without a thermocouple.

Backing plates are either mica or mica-calendared Nomex sheets, or epoxy upon User provision. Figure 4 and 5 show one of the possibilities for preparing and arranging them. 2 plates with no cutouts for the top and bottom of the assembly. 2 plates with a cutout for the beam. And 2 more with cutouts for the beam and metal (typically copper) electrodes. Before placing plates with electrodes, consult your LC for the current position of the heating cables in the LVP. Glue each plate on cubes using superglue.

Figure 4. Preparation of mica/epoxy sheets.

 

Figure 5. Arrangements of backing plates for 6/8 assembly.

6/8 Octahedron

For 6/8, pressure media is an octahedron made of MgO sintered with Cr2O3. It requires windows cut and replaced by an amorphous x-ray transparent material. High-pressure and high-temperature experiments require the cell assembly is composed of the sample (preferably in the capsule) and the furnace/heater. Additionally, the thermal insulator (ZrO2), the electrodes, the thermocouple, etc. can or should be used.

  

 
   

Figure 4. A cross-section of  a10 mm HP-HT assembly with its main components.

  

 

Figure 5. A 3-D model of an octahedron of the 10 mm assembly.

Furnace

Graphite furnaces are preferrentially used for the 6/8 experiments, while the transition metal or LaCrO3 ones are possible as well. Electrical and thermal insulation of the sample is ensured by usage of BN sleeves (around the sample capsules or as sample containers) as well as ZrO2 or MgO rods. The latter are inserted above and below the sample and thus are out of the beam path. Alternatively, metalic furnaces are possible (Re, Mo and etc.).

Capsule

Capsule materials are usualy graphite, NaCl or metal.