... in the piston-cylinder apparatus. In order to minimize the possibility of rupture of the AuPd capsule and to control H 2 O loss we used a double-capsule method. The inner welded 2 mm diameter Au 80 Pd 20 capsule was placed inside a welded 3 mm diameter Pt capsule, the intervening space being packed with hydrous...

..., demonstrating that Fe alloying has been successfully counteracted. Combination of AuPd containers with Fe pre-enriched starting materials offers excellent perspectives to solve the Fe loss issue in high-pressure experiments on basaltic compositions. * E-mail: [email protected]...

... of Au 74 Pd 26 with iron using an asymmetric regular solution leads to W G-Fe = −45.0 ± 1.8 kJ/mol and W G-AuPd = +19.5 ± 7.7 kJ/mol (1σ). Internal oxidation of iron was observed in a reversal experiment, suggesting that oxygen can be transferred across capsule boundaries during high-temperature...

.... Optimum results were obtained by using Fe-preconditioned Au 90 Pd 10 inner capsules in combination with MgO assemblies. The application of the modified double-capsule technique with Fe-preconditioned inner AuPd capsules reduced Fe loss to less than 3% relative, conserved H 2 O within the error of ion...

... of the experiment (see text for more information). ‡‡ This experiment was run for 15 hours at 1300 °C and 15 hours at 1175 °C. §§ Only brucite added. Piston-cylinder R056 1.91 cm 2(1.8) 1300 8.4 48 AuPd none 9.9 154.4 (fg, KLB) na Yes†† 375 115/54 Multi-anvil (Fe-bearing) ww296...

... coating on the specimen ( Bradley et al., 1997 ; Bradley, 1999 ). Testing of various coating approaches, however, showed that AuPd coatings of 10–20 nm thickness do not produce artifacts that could be mistaken for microbial remains ( Clanton and Morrison, 1979 ; McKay et al., 1997 ). Beam heating...

...F igure 2. Coating test on synthetic methane hydrate. This sample was fractured at ∼100 K under vacuum, initially imaged uncoated at 2 kV and 100 K ( a ), then reinserted in the cryo-preparation chamber and coated with AuPd for 120 seconds at 100 K. The same general area of the sample...

... for capsule materials (Au or AuPd alloy). ...

... equilibrated in air (blue circle) and equilibrated at ΔNNO = –1 (blue triangle); the latter is the pre-saturation run condition for all AuPd capsules. The green triangles are calculated glass Fe 3+ /Fe T ratios, based on f O 2 calculated from analyzed Fe content in Au-Pd capsules of run products ( Barr...

...F igure 4. Backscattered electron images of experimental charges. ( a ) Experiment M393 at 1200 °C and 3 GPa. Ol = olivine crystal; Ol+opx+Fe = olivine, orthopyroxene, and iron metal intergrowth; AuPd = capsule material; Liq = quench crystals and voids representing quenched hydrous silicate...

..., 1971 ). Commonly used metals and alloys are Au, Pt, Ag, AuPd, and AgPd. Although called “noble”, none of these materials is completely inert, with the degree of reactivity increasing with increasing temperature. At temperatures above ~600 °C, (1) Au significantly alloys with Cu, (2) Pt (at high T...

... the same method as for AuPd capsules and Mo foils were dried at 140 °C for 1h. Stepped LaCrO 3 furnaces with Mo electrodes were used for the two series of experiments. The furnace was separated from the capsule by an MgO spacer. A W 95 Re 5 -W 74 Re 26 thermocouple was inserted axially...

... a crystallographically oriented single crystal of forsterite within ~60 mg of the kimberlitic starting material, in 4 mm outer diameter and 7 mm length gold-palladium (Au 75 Pd 25 ; simply AuPd from now on) capsules (see Fig. 1 ), which were then welded. AuPd capsules were chosen to minimize water loss. Single crystals...