Versatile compact heater design forin situnano-tomography by transmission X-ray microscopy

Abstract

A versatile, compact heater designed at National Synchrotron Light Source-II for in situ X-ray nano-imaging in a full-field transmission X-ray microscope is presented. Heater design for nano-imaging is challenging, combining tight spatial constraints with stringent design requirements for the temperature range and stability. Finite-element modeling and analytical calculations were used to determine the heater design parameters. Performance tests demonstrated reliable and stable performance, including maintaining the exterior casing close to room temperature while the heater is operating at above 1100°C, a homogenous heating zone and small temperature fluctuations. Two scientific experiments are presented to demonstrate the heater capabilities: (i) in situ 3D nano-tomography including a study of metal dealloying in a liquid molten salt extreme environment, and (ii) a study of pore formation in icosahedral quasicrystals. The progression of structural changes in both studies were clearly resolved in 3D, showing that the new heater enables powerful capabilities to directly visualize and quantify 3D morphological evolution of materials under real conditions by X-ray nano-imaging at elevated temperature during synthesis, fabrication and operation processes. This heater design concept can be applied to other applications where a precise, compact heater design is required.

A Brief Guide to the Structure of High-Temperature Molten Salts and Key Aspects Making Them Different from Their Low-Temperature Relatives, the Ionic Liquids

“…There has been a constant stream of articles − including salts in their molten or glass states since the early 1900s; see for example, the works of Zachariasen and Rosenhain . Yet, through the years, molten salts continue to be rediscovered for applications in energy technologies including nuclear energy, − solar energy harvesting, − batteries, − and separations to mention just a few.…”

“…Recently, a faster Drude-type model that includes some of the same ingredients as in these other more expensive models has also been successfully developed and applied to the case of MgCl 2 and its mixtures with KCl . A variety of articles based on machine-learning simulation schemes for molten salts have also recently appeared in the literature. − Advances in computational models have come hand-in-hand with new experimental studies, ,,,− ,− and in some cases, the combination of these challenges strongly entrenched assumptions, for example the octahedral coordination of U 3+ , the tetrahedrality in coordination for Mg 2+ , , and other properties that collectively have influenced the literature for 30 years or more. ,− The works cited thus far are meant to provide some context and are not exhaustive or cover many of the most studied salts and their mixtures of which the eutectics are of special relevance.…”

Effect of the grain arrangements on the thermal stability of polycrystalline nickel-rich lithium-based battery cathodes

“…In this study, we measured three particles at different locations in the heating chamber independently for each type of NMC material, all particles showed similar behaviors as a function of temperature. A more detailed description of this technique, experimental setups, and explanation of temperature range selection for the in situ measurements can be found in Supplementary Note 1 and previous research works 24 – 27 .…”

Formation of three-dimensional bicontinuous structures via molten salt dealloying studied in real-time by in situ synchrotron X-ray nano-tomography

“…In situ X-ray nano-tomography experiments were conducted at the FXI beamline (FXI, 18-ID) at NSLS-II of Brookhaven National Laboratory 49 . The assembled sample of Ni–20Cr wire in 50:50 molar KCl–MgCl 2 was mounted onto a TXM sample holder and placed into a miniature furnace integrated with the TXM at FXI, which was jointly developed by NSLS-II and the Molten Salts in Extreme Environments Energy Frontier Research Center 83 . This sample was heated to 800 °C with a ramp rate of 25 °C min, held at 800 °C for 4 h, then cooled to room temperature with a ramp rate of 50 °C min −1 .…”