Perovskites, particularly perovskite hydrides, have gained significant attention in materials science due to their unique properties and potential applications in various fields such as sustainable energy technologies, catalysis, and optoelectronics. Perovskite hydrides are of special interest because of their hydrogen-derived properties and their potential role in the development of hydrogen storage technologies like fuel cells and next-generation batteries, as well as energy-efficient superconducting cables. However, characterizing the physical properties of perovskite hydrides, especially their H− conductivity, has been challenging due to the irregularities in powdered samples used in most studies.
In a recent study published in ACS Applied Energy Materials, a team of researchers from the Shibaura Institute of Technology in Japan, led by Doctoral course student Erika Fukushi, developed a novel approach to produce high-quality single crystals of ternary perovskite hydrides for intrinsic conduction measurements. The team utilized a method called ‘H-radical reactive infrared laser deposition’ to grow single crystals of MLiH3 (where M is Sr or Ba) on a substrate by releasing metal atoms from a pellet containing MH2 and LiH powders into a hydrogen-rich atmosphere. This method allowed for the epitaxial growth of nanofilms with consistent crystal layers, free from grain boundaries.
The researchers extensively characterized the thin films using advanced techniques such as X-ray diffraction, atomic force microscopy, and scanning electron microscopy to determine the elemental distribution and crystallinity of the films. By optimizing the experimental conditions, the team was able to grow well-ordered, single-crystal MLiH3 films without grain boundaries, enabling them to conduct intrinsic H− conductivity measurements for the first time. These measurements provided crucial information for the development of novel secondary batteries and fuel cells based on hydride-ion conduction, which could accelerate the adoption of electric vehicles and renewable energy sources for a sustainable society.
The successful production and characterization of high-quality perovskite hydride crystals using the innovative deposition method developed by the research team represent a significant advancement in hydrogen materials science. By obtaining accurate measurements of the intrinsic H− conductivity of ternary perovskite hydrides, the researchers have opened up new possibilities for the development of hydrogen-related technologies and have laid the foundation for future research in this field. This breakthrough could propel the field of materials science towards more sustainable energy solutions and contribute to the creation of a greener, more energy-efficient society in the future.