A new compact symmetric rotational diamond anvil cell for in situ high-pressure-torsion studies

TL;DR

This paper introduces a compact symmetric rotational diamond anvil cell designed for in situ high-pressure torsion studies, improving reliability and scope of high-pressure shear experiments on materials.

Contribution

A novel symmetric design for a rotational diamond anvil cell that enhances measurement accuracy and enables advanced high-pressure shear studies.

Findings

Improved crystallographic orientation distribution measurement.

Enhanced stress state and lattice strain analysis.

Successful demonstration of the device's advantages.

Abstract

In situ studies under severe plastic deformation at high pressures, employing rotational/shear diamond anvil cells (RDAC), have recently gained much interest in the high-pressure community owing to their potential applications in material processing methods, mechanochemistry, geophysics, etc. These studies, combined with multi-scale computational simulations, provide important insights into the transient hierarchical microstructural evolution, structural phase transitions, and orientation relationship between parent and daughter phases and help establish the kinetics of strain-induced phase transitions under severe plastic deformation. Existing RDACs are mostly used in axial x-ray diffraction geometry due to geometrical constraints providing less reliable information about stress states and texture. Their asymmetric design also poses serious limitations to high-pressure shear studies on single crystals. To overcome these limitations, a new compact symmetric rotational diamond anvil cell has been designed and developed for in situ high-pressure torsion studies on materials. The symmetric angular opening and short working distance in this new design help obtain a more reliable crystallographic orientation distribution function and lattice strain states up to a large Q range. Here, we present the advantages of the symmetric design with a few demonstrative studies.