Metal–insulator transition in composition-tuned nickel oxide films

• Published in: Journal of physics. Condensed matter 2023-04, Vol.35 (30)
• Main Authors: Fowlie, Jennifer, Georgescu, Alexandru B., Suter, Andreas, Mundet, Bernat, Toulouse, Constance, Jaouen, Nicolas, Viret, Michel, Domínguez, Claribel, Gibert, Marta, Salman, Zaher, Prokscha, Thomas, Alexander, Duncan T. L., Kreisel, Jens, Georges, Antoine, Millis, Andrew J., Triscone, Jean-Marc
• Format: Article
• Language: English
• Subjects: Physics
• ISSN: 0953-8984

Abstract Thin films of the solid solution Nd 1−x La x NiO3are grown in order to study the expected 0 K phase transitions at a specific composition. We experimentally map out the structural, electronic and magnetic properties as a function ofxand a discontinuous, possibly first order, insulator–metal transition is observed at low temperature whenx= 0.2. Raman spectroscopy and scanning transmission electron microscopy show that this is not associated with a correspondingly discontinuous global structural change. On the other hand, results from density functional theory (DFT) and combined DFT and dynamical mean field theory calculations produce a 0 K first order transition at around this composition. We further estimate the temperature-dependence of the transition from thermodynamic considerations and find that a discontinuous insulator–metal transition can be reproduced theoretically and implies a narrow insulator–metal phase coexistence withx. Finally, muon spin rotation (µSR) measurements suggest that there are non-static magnetic moments in the system that may be understood in the context of the first order nature of the 0 K transition and its associated phase coexistence regime.