Cold Sintering Process: A Novel Technique for Low‐Temperature Ceramic Processing of Ferroelectrics

TLDR

Sintering of dense ceramics has been a focus of research for decades, yet most techniques still require high temperatures. The article presents a comprehensive tutorial on the Cold Sintering Process using KH₂PO₄, NaNO₂, and BaTiO₃, aiming to guide future ultralow‑temperature ceramic sintering research. The authors detail experimental demonstrations, fundamental mechanisms, and thermodynamic physics underlying the Cold Sintering Process. The Cold Sintering Process achieves dense ceramics below 300 °C across diverse chemistries, offering a cost‑effective, energy‑saving alternative to conventional high‑temperature sintering.

Abstract

Research on sintering of dense ceramic materials has been very active in the past decades and still keeps gaining in popularity. Although a number of new techniques have been developed, the sintering process is still performed at high temperatures. Very recently we established a novel protocol, the “Cold Sintering Process ( CSP )”, to achieve dense ceramic solids at extraordinarily low temperatures of <300°C. A wide variety of chemistries and composites were successfully densified using this technique. In this article, a comprehensive CSP tutorial will be delivered by employing three classic ferroelectric materials ( KH 2 PO 4 , Na NO 2 , and BaTiO 3 ) as examples. Together with detailed experimental demonstrations, fundamental mechanisms, as well as the underlying physics from a thermodynamics perspective, are collaboratively outlined. Such an impactful technique opens up a new way for cost‐effective and energy‐saving ceramic processing. We hope that this article will provide a promising route to guide future studies on ultralow temperature ceramic sintering or ceramic materials related integration.