Speaker
Description
The discovery of superconductivity in doped infinite-layer nickelate thin films has stimulated considerable interest in understanding the role of different dopants. Among these, magnetic rare-earth doping occupies a particularly distinctive position. Eu-doped NdNiO2 gives rise to a striking field-induced re-entrant superconductivity, which emerges from a delicate balance between the competing spin polarizations of the Eu2+ and Nd3+ ions [1]. This interplay produces a net suppression of the internal magnetic field over an intermediate field range. To directly probe the underlying spin polarization of both magnetic species, X-ray magnetic circular dichroism (XMCD) measurements are employed.
Turning to the doping landscape more broadly, a notable asymmetry is apparent: existing studies of the 113-perovskite parent compound thin films have mainly concentrated on the hole-doped regime, with electron-doping investigations largely confined to bulk materials. To tackle this imbalance, a systematic study of electron doping in NdNiO3 thin films via A-site substitution is presented. Pb is employed as a dopant, exploiting its valence-skipping character to inject electrons into the nickelate framework [2]. This work establishes A-site Pb substitution as a viable and controlled route to electron doping in rare-earth nickelate thin films.
References
[1] L. Varbaro et al. arXiv:2601.19473 (2026).
[2] M. Hadjimichael et al. Adv. Electron. Mater. 2201182 (2023).