Tunable resistivity exponents in the metallic phase of epitaxial nickelates
Daten & Fakten
10.03.2020
14:00 – 15:30 Uhr
Speaker:
Prof. Dr. Beatriz Noheda
Zernike Institute for Advanced Materials and CogniGron
University of Groningen
Groningen, The Netherlands
Time and Place:
Tuesday, 10.03.2020, 14:00 Uhr
IFW Dresden, Room B3E.26, Helmholtzstraße 20, 01069 Dresden
Biography:
Prof. Beatriz Noheda received her PhD in Experimental Physics from the Department of Physics,
Universidad Autonoma de Madrid (UAM), Spain. After several post-doctoral positions as Lecturer,
Assistant Physicist, Research Fellow and Assistant/Associate Professor in Madrid, Brookhaven,
Amsterdam, and Groningen, she was promoted in 2014 to become Full Professor at the Zernike Institute
for Advanced Materials, Groningen, as well as leading the Groningen Cognitive Systems and Materials
Center “CogniGron” as its director. Her research focuses on ferroic materials and nanostructures
thereof, with special emphasis on the bottom-up assembly of tailor-made materials with distinct
functionalities (conductivity, polarity, magnetism) and applications (neuromorphic computing, etc.).
Überblick
Rare earth nickelates (ReNiO3) undergo a metal-insulator transition (MIT) that can be tuned
both chemically (choice of Re) and physically (strain or electric field). Nickelates hold great
promise for resistive switching applications, such as for memories or adaptable electronics.
The interest on these materials has recently increased even further due to the finding of
superconductivity on the related family of infinite-layer nickelates[1]. However, a complete
understanding of the metallic phase in these strongly correlated electron systems is still one
of the central open problems in condensed matter physics. For instance, nickelates have been
proposed to behave both as bad metals[2] and as normal metals[3] by different researchers.
Moreover, the behavior of the nickelates as Fermi-liquid or non-Fermi liquid systems is also
highly debated, as various scaling exponents of the resistivity as a function of temperature
have been reported in the same materials [3,4].
In this talk, I will show that the resistivity-temperature exponent in epitaxially-grown NdNiO3
films can be continuously tuned by the combined effect of epitaxial strain and disorder[5],
validating previous theoretical results by Patel et al [6]. Therefore, the assignment of Fermi
liquid/non-Fermi liquid behavior from the resistivity-temperature exponents is not always
justified and a detail micro-structural characterization is needed. In addition, I will describe
our latest experiments that aim to establish the nature of the metallic behavior in the NdNiO3.
[1] D. Li, et al., Nature 572, 624 (2019).
[2] R. Jaramillo, et al., NPhysics 10, 304 (2014).
[3] E. Mikheev, et al., Sci, Adv. 1, e1500797 (2015).
[4] J. Liu, et al., NComms. 4, 2714 (2013).
[5] Q. Guo, B. Noheda, et al., https://arxiv.org/abs/1909.06256.
[6] N.D. Patel, et al., Phys. Rev. Lett. 119, 086601 (2017).