Structure and properties of complex hydride perovskite materials

Area of Science:

• Materials Science
• Solid-State Chemistry
• Inorganic Chemistry

Background:

• Perovskite materials are known for diverse functionalities.
• Hydrogen, as a hydride anion (H-), has been incorporated into oxide perovskites.
• Complex hydrides offer new avenues for functional materials.

Purpose of the Study:

• To present a series of 30 new complex hydride perovskite-type materials.
• To explore their photophysical, electronic, and hydrogen storage properties.
• To investigate the role of tetrahydroborate (BH4-) anions in perovskite structures.

Main Methods:

• Synthesis of new complex hydride perovskites involving rare-earth elements.
• Theoretical investigation of electronic structure using density functional theory (DFT) solid-state calculations.
• Analysis of anion dynamics and structural behavior, including supercell formation.

Main Results:

• Discovery of 30 new complex hydride perovskites based on the BH4- anion.
• Observation of unique photophysical, electronic, and hydrogen storage properties.
• BH4- anion dynamics were found to stabilize lattice structures and induce supercell formation (up to 16x unit cell volume).
• Homopolar hydridic di-hydrogen contacts were identified as key for tailoring crystal symmetries.
• Anion mixing (BH4- with halides) established a link to known ABX3 halide perovskites.

Conclusions:

• Complex hydride perovskites incorporating BH4- anions represent a new class of functional materials.
• BH4- dynamics offer novel mechanisms for controlling perovskite structures and properties.
• These findings bridge molecular chemistry concepts with ceramic-like host lattices.
• The study opens pathways for designing materials with tailored electronic and hydrogen storage capabilities.