Diamond anvil apparatus

H. K. Mao, P. M. Bell, and C. Hadidiacos, Experimental phase relations of iron to 360 kbar, 1400°, determined in an internally heated diamond anvil apparatus, in High-Pressure Research in Mineral Physics, M. H. Manghnani and Y. Syono, eds., Terra Scientific Publishing Co., Tokyo, and American Geophysical Union, Washington DC, 1987, pp. 135-138. 

FIGURE 6 Cross section of diamond anvil apparatus with small central face and tapered flanks, for P > 20 MPa. 

Liquid formaldehyde is not available commercially, and exists only at low temperatures. Our chemical procedure for producing liquid formaldehyde was as follows Into a dried 500 mL 3-necked round-bottomed fitted with a N2 inlet and outlet, thermocouple, and surrounded by a heating mantle was placed approximately 80g of paraformaldehyde (fills flask 2/3 full). The mixture was heated to decompose the paraformaldehyde with the internal temperature controlled with a thermocouple connected to a temperature controller set at 150 C. The formaldehyde was initially collected (under a slow N2 flow) in a small condensing trap cooled at CO2/ acetone temperature to insure removal of residual water and any low boiling impurities. After about 5 mL of formaldehyde was collected in the trap the outlet tube was coimected to the diamond anvil apparatus, which was kept under a N2 atmosphere and cooled to dry ice/ acetone temperatures. Enough formaldehyde was collected to completely cover the diamond anvil cell ( 20 mL). The cell was opened and then closed to encapsulate the sample. A rhenium gasket was used to radially confine the diamond anvil cell samples. 

Hydrothermal experiments were performed with a hydrothermal diamond anvil apparatus (HDAC) after Basset et al. [34], which was modified and is described elsewhere [35]. Pure tridestilled water was used as a medium and the pressure was calculated with the aid of the equations of state (EOS) of pure water substance.[36, 37]. Samples were heated with 20 Kmin" up to 500°C. This temperature, which corresponds to an isochoric pressure of 500 -770 MPa, was maintained 1 K for 5 h before cooling to room temperature with the same gradient. 

Similar qualitative observations with diamond anvil apparatus have shown that Yb monochalcogenides undergo the electronic transition near about 200 kbar pressure (Jayaraman et al., 1974). At high pressures YbS acquires a golden yellow color, YbSe a copperish luster and YbTe a purple color, reminiscent of the changes observed in SmS, SmSe and SmTe at high pressure. In table 20.3 data obtained from pressure experiments are presented. 

Examples of barophUes include Moritella and Shewanella species that laboratory experiments suggest can grow at 70 MPa, but not at pressures of 50 MPa [28], suggesting they are true barophiles. Similar bacteria have been obtained from the Mariana Trench. More remarkable evidence has been presented for growth using a diamond anvil apparatus. Shewanella oneidensis and Escherichia coli were reported to remain physiologically active at pressures up to 1,680 MPa for up to 30 h [29]. As for low temperatures, the pressure limits for life remain unknown. 

Formed by pressure diffusion from CujS in a pressure gradient of a diamond anvil apparatus. 

The development of a squeezer apparatus for optical studies by Drickamer and his coworkers (Fitch et al., 1957) and almost at the same time the development of the diamond anvil cell (DAC) (Weir et al., 1959 Jamieson et al., 1959) provided real breakthrough in the... 

FIGURE 12 Pressure versus depth in Earth. Crust, mantle, and core boundaries and densities are indicated along with pressures attainable with the diamond anvil and large-volume static apparatus. 

Figure 6 Essential parts of high pressure apparatus of (a) the Bridgman type, (h) the belt type, (c) the cubic anvil type, (d) the 6-8 split sphere anvil type, and (e) the diamond anvil type...

Crystals that are unaffected by air, moisture, or light are usually mounted directly on a quartz or glass fiber, which is inserted into a goniometer head (Figure 14.3). If the crystal is sensitive to moisture or air, a sealed capillary tube may be used. Suitable apparatus can be used when nonambient temperatures and pressures are needed. The diamond anvil has been developed for high pressure. 

The e - y transition boundary was determined by measuring the resistance changes during the transition in a high-compression belt apparatus (Bundy, 1965) and in an internally heated diamond-anvil cell (Boehler, 1986 Mao et al, 1987). The boundary was also determined by in situ X-ray diffraction measurements in an internally heated diamond-anvil cell (Boehler, 1986 Dubrovinsky et al, 1998), in a laser-heated diamond-anvil cell (Shen et al, 1998), and in a multi-anvil apparatus (Funamori et al, 1996 Lfchida et al, 2001). The boundaries determined by Mao et al. (1987), Shen et al (1998), and Lfchida et al (2001) are in good agreement, but are all at —75 K higher temperature (or —2 GPa lower pressure) than the boundary determined by Funamori et al. (1996), Boehler (1986), and Bundy (1965). 

The eutectic temperamre of the Fe-S binary system has been measured in a multi-anvil apparatus to 25 GPa (Fei et al, 1997, 2000 Li et al, 2001), and in a laser-heated diamond-anvil cell to 62 GPa (Boehler, 1996). Within the common pressure range, the diamond-anvil cell results are higher than the multi-anvil apparams results by as much as 400°. Despite the discrepancies, the existing data show that between... 

The volume—pressure relationship for e-Fe has been determined up to 300 GPa at room temperature (Figure 3 Mao et al., 1990). Determining the temperature dependence of the bulk modulus of iron is crucial for accurate comparison between the density of iron and that of the iimer core. Several in situ X-ray diffraction studies in the diamond-anvil cell (Huangeta/., 1987 Dubrovinsky eta/., 1998, 2000) and in the multi-anvil apparatus (Funamori et al., 1996 Uchida et al., 2001) have provided limited data on the thermal expansion of e-Fe at high pressures. The data of Dubrovinsky et al. 

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