TY  - JOUR
AU  - Oppliger, Jens
AU  - Küspert, Julia
AU  - Dippel, Ann-Christin
AU  - v. Zimmermann, Martin
AU  - Gutowski, Olof
AU  - Ren, Xiaolin
AU  - Zhou, Xingjiang
AU  - Zhu, Zhihai
AU  - Frison, Ruggero
AU  - Wang, Qisi
AU  - Martinelli, Leonardo
AU  - Biało, Izabela
AU  - Chang, Johan
TI  - Discovery of giant unit-cell super-structure in the infinite-layer nickelate PrNiO<sub>2+x</sub>
JO  - Communications materials
VL  - 6
IS  - 1
SN  - 2662-4443
CY  - London
PB  - Springer Nature
M1  - PUBDB-2025-00169
SP  - 3
PY  - 2025
AB  - The discovery of unconventional superconductivity often triggers significant interest in associated electronic and structural symmetry breaking phenomena. For the infinite-layer nickelates, structural allotropes are investigated intensively. Here, using high-energy grazing-incidence x-ray diffraction, we demonstrate how in-situ temperature annealing of the infinite-layer nickelate PrNiO<sub>2+x</sub> (x ≈ 0) induces a giant superlattice structure. The annealing effect has a maximum well above room temperature. By covering a large scattering volume, we show a rare period-six in-plane (bi-axial) symmetry and a period-four symmetry in the out-of-plane direction. This giant unit-cell superstructure—likely stemming from ordering of diffusive oxygen—persists over a large temperature range and can be quenched. As such, the stability and controlled annealing process leading to the formation of this superlattice structure provides a pathway for novel nickelate chemistry. 
LB  - PUB:(DE-HGF)16
C6  - pmid:39780911
UR  - <Go to ISI:>//WOS:001390550100001
DO  - DOI:10.1038/s43246-024-00729-4
UR  - https://bib-pubdb1.desy.de/record/622083
ER  -