A double-walled sapphire single-crystal gas-pressure cell (type III) for in situ neutron diffraction

In situ neutron diffraction is an important characterization technique for the investigation of many functional materials, e.g. for hydrogen uptake and release in hydrogen storage materials. A new sapphire single-crystal gas-pressure cell for elastic neutron scattering has been developed and evaluated; it allows conditions of 298 K and 9.5 MPa hydrogen pressure and 1110 K at ambient pressure. The pressure vessel consists of a sapphire single-crystal tube of 35 mm radius and a sapphire single-crystal crucible as sample holder. Heating is realized by two 100 W diode lasers. It is optimized for the D20 diffractometer, ILL, Grenoble, France, and requires the use of a radial oscillating collimator. Its advantages over earlier sapphire single-crystal gas-pressure cells are higher maximum temperatures and lower background at low and high diffraction angles. The deuterium uptake in palladium was followed in situ for validation, proving the potential of the type-III gas-pressure cell for in situ neutron diffraction on solid–gas reactions.

Validation of a Sapphire Gas-Pressure Cell for Real-Time In Situ Neutron Diffraction Studies of Hydrogenation Reactions

A gas-pressure cell, based on a leuco-sapphire single-crystal, serving as a pressure vessel and sample holder, is presented for real time in situ studies of solid-gas hydrogenation reactions. A stainless steel corpus, coated with neutron absorbing varnish, allows alignment for the single-crystal sample holder for minimizing contributions to the diffraction pattern. Openings in the corpus enable neutron scattering as well as contactless temperature surveillance and laser heating. The gas-pressure cell is validated via the deuteration of palladium powder, giving reliable neutron diffraction data at the high-intensity diffractometer D20 at the Institut Laue-Langevin (ILL), Grenoble, France. It was tested up to 15.0 MPa of hydrogen pressure at room temperature, 718 K at ambient pressure and 584 K at 9.5 MPa of hydrogen pressure.

Design and use of a sapphire single-crystal gas-pressure cell for in situ neutron powder diffraction

A sapphire single-crystal gas-pressure cell without external support allowing unobstructed optical access by neutrons has been developed and optimized for elastic in situ neutron powder diffraction using hydrogen (deuterium) gas at the high-intensity two-axis diffractometer D20 at the Institut Laue-Langevin (Grenoble, France). Given a proper orientation of the single-crystal sample holder with respect to the detector, parasitic reflections from the sample holder can be avoided and the background can be kept low. Hydrogen (deuterium) gas pressures of up to 16.0 MPa at 298 K and 8.0 MPa at 655 K were tested successfully for a wall thickness of 3 mm. Heating was achieved by a two-sided laser heating system. The typical time resolution of in situ investigations of the reaction pathway of hydrogen (deuterium) uptake or release is on the order of 1 min. Detailed descriptions of all parts of the sapphire single-crystal gas-pressure cell are given, including materials information, technical drawings and instructions for use.

Will Magnetic Properties near Pressure Induced Quantum Critical Phenomena Be Elucidated?

Hiraoka et al. developed an opposed anvil-type pressure cell for magnetization measurements which combines a large sample space and is capable of generating higher pressures up to 6.3 GPa.