Superconducting nickelates gained rapid attention after superconductivity was first discovered in thin-film nickelate compounds in 2019. This breakthrough confirmed the long-standing idea that nickelates could echo the key aspects of cuprates, drawing broad interest across the community. Since then, their structural flexibility, especially the way oxygen can be selectively removed, has become a major focus for understanding how lattice chemistry drives unconventional superconductivity.

In close collaboration with Prof. B. Keimer and Dr. M. Hepting, our 2021 Science Advances paper showed that topotactic reduction can be extended from powders and thin films to high-quality single crystals, allowing access to bulk phases beyond what is typically achievable in thin films. In our 2024 PRL paper, we showed that the superconducting La3Ni2O7 exhibits a more intricate stacking arrangement than previously proposed, offering a refined structural perspective for interpreting its high-pressure behavior.

In our 2023 PRM paper, we resolved a brownmillerite-like arrangement of oxygen vacancies as an intermediate state during topotactic reduction in nickelates. 

We also showed in our 2024 APL Materials paper how the topotactic reduction of perovskite nickelates evolves through a variety of nanoscale structural responses toward the infinite-layer phase, providing a clearer picture of the topotactic process in nickelate crystals.