Striped nanoscale phase separation at the metal-insulator transition of heteroepitaxial nickelates.
Nucleation processes of mixed-phase states are an intrinsic characteristic of first-order phase transitions, typically related to local symmetry breaking. Direct observation of emerging mixed-phase regions in materials showing a first-order metal-insulator transition (MIT) offers unique opportunities to uncover their driving mechanism. Using photoemission electron microscopy, we image the nanoscale formation and growth of insulating domains across the temperature-driven MIT in NdNiO3epitaxial thin films. Heteroepitaxy is found to strongly determine the nanoscale nature of the phase transition, inducing preferential formation of striped domains along the terraces of atomically flat stepped surfaces. We show that the distribution of transition temperatures is a local property, set by surface morphology and stable across multiple temperature cycles. Our data provide new insights into the MIT of heteroepitaxial nickelates and point to a rich, nanoscale phenomenology in this strongly correlated material.
Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands.
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0000-0002-3678-9168
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Mattoni
London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, 17-19 Gordon Street, London WC1H 0HA, UK.
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P
Zubko
Diamond Light Source, Harwell Science and Innovation Campus, Chilton OX11 0DE, UK.
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F
Maccherozzi
Kamerlingh Onnes-Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, Netherlands.
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AJ
van der Torren
Kamerlingh Onnes-Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, Netherlands.
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DB
Boltje
London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, 17-19 Gordon Street, London WC1H 0HA, UK.
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M
Hadjimichael
Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands.
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0000-0002-7768-2500
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Manca
Département de Physique de la Matière Quantique, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Genève 4, Switzerland.
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S
Catalano
Département de Physique de la Matière Quantique, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Genève 4, Switzerland.
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M
Gibert
Diamond Light Source, Harwell Science and Innovation Campus, Chilton OX11 0DE, UK.
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Y
Liu
Kamerlingh Onnes-Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, Netherlands.
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J
Aarts
Département de Physique de la Matière Quantique, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Genève 4, Switzerland.
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JM
Triscone
Diamond Light Source, Harwell Science and Innovation Campus, Chilton OX11 0DE, UK.
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SS
Dhesi
Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, Netherlands.
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Caviglia