Large-volume cubic press produces high temperatures above 4000 Kelvin for study of the refractory materials at pressures

Abstract

The advent of a large-volume high-pressure apparatus has led to the discovery of many new materials with exceptional properties for widespread applications such as superhard materials (e.g., diamonds). However, for most conventional devices, the pressure and temperature capabilities are often limited to 6 GPa and 2300 K, which severely impedes the study of materials at extended pressures and temperatures. In this work, we present experimental optimizations of the high-pressure cell assembly for cubic press with a focus on the improvement of its temperature capability, leading to a record temperature value of ∼4050 K and largely extended pressure conditions up to ∼10 GPa with a centimeter-sized sample volume. Pressures of the new assembly at high temperatures are investigated by the melting-point method, giving rise to a series of parallel isoforce loading lines associated with thermally induced pressure. For the first time, the high-pressure melting curve of tungsten carbide is determined up to 3800 K and 8 GPa, and single-crystal refractory materials of Mo, Ta, and WC are also grown using the optimized cell.

Synthesis, Crystal Structures, Mechanical Properties, and Formation Mechanisms of Cubic Tungsten Nitrides

“…Thanks to our recent instrumental advancements, the temperature capability of our large-volume cubic press has been successfully extended up to 3770 °C, allowing the exploratory synthesis of more metastable TM nitrides at higher temperatures . By exploiting this technique, two cubic W–N phases are prepared at 3–5 GPa and temperatures of 1600–2400 °C (Figure S1), using our recently formulated reaction route, ,,, given by …”

“…High P – T experiments were carried out in a DS 6 × 10 MN cubic press installed in the high- P lab of SUSTech . Before the experiment, the mixed sample powders were compacted into a cylindrical pellet 6 mm in length and 10.7 mm in diameter, which was then loaded in a Mo capsule to avoid contamination.…”

A Review of the Melting Curves of Transition Metals at High Pressures Using Static Compression Techniques

“…Large volume presses (LVP) such as the piston-cylinder or the multi-anvil press [110,111] are widely used for the synthesis of materials, especially when the production of large single crystals is essential [112,113]. Record temperatures of 4050 K [114] and pressures of 90 GPa [115] have been reported for multi-anvil presses, although for most conventional devices in laboratories and synchrotrons the maximum pressure is limited to 25 GPa and the maximum temperature to 2500 K. Therefore, the routinely obtainable P-T range in the LH-DAC (or RH-DAC) is much greater than that of a multi-anvil press, but the precision to which the melting temperature can be determined in a DAC is, in general, much lower.…”

Growth of Millimeter Size B6O Single Crystals in a B-H3BO3 System at High Pressure and High Temperature

“…High P–T experiments were carried out in DS6 × 14MN and DS6 × 10MN cubic presses using previously reported P and T calibrations. − The starting materials of amorphous boron (a-rhombohedral, >96.6% purity, Aladdin Co., China) and H 3 BO 3 (>99.9% purity, Aladdin Co., China) were mixed in a molar ratio of B/H 3 BO 3 = 16:2.4. Excess boric acid was used to eliminate boron from the final product.…”

“…Excess boric acid was used to eliminate boron from the final product. The mixtures were homogeneously ground and compressed into pellets of 6 mm diameter and 6 mm height, and then loaded into an hBN capsule. , The samples were compressed to a desired pressures of 3–5.5 GPa before heating to 600–2200 °C for 20 min and then cooled to a room temperature at a rate of 100 °C/min. The recovered samples were washed with boiling water for several hours to completely remove possible impurities.…”