Investigating the electromechanical behavior of unconventionally ferroelectric Hf_0.5Zr_0.5O₂-based capacitors through operando nanobeam X-ray diffraction

Evgenios Stylianidis ^1,2 Pranav Surabhi ³ Ruben Hamming-Green ¹ Mart Salverda ¹ Yingfen Wei ^1,4 Arjan Burema ¹ Sylvia Matzen ⁶ Tamalika Banerjee ¹ Alexander Björling ⁵ Dina Carbone ⁵ Beatriz Noheda ^1,7 Pavan Nukala ^1,3

¹Zernike Institute for Advanced Materials, University of Groningen, Groningen, Netherlands
²Department of Physics and Astronomy, Univeristy College London, London, UK
³Center for Nanoscience and Engineering, Indian Institute of Science, Bengaluru, India
⁴Frontier Institute of Chip and System, Fudan Univeristy, Shanghai, China
⁵MAX IV Laboratory, Lund University, Lund, Sweden
⁶Center for Nanoscience and Nanotechnology, Paris-Saclay University, Palaiseau, France
⁷CogniGron center, University of Groningen, Groningen, Netherlands

Understanding various aspects of unconventional ferroelectricity in hafnia-based materials is of major importance for the development of future non-volatile memory and logic devices. Here, we investigate the unconventional and weak electromechanical response of epitaxial La_0.67Sr_0.33MnO₃/Hf_0.5Zr_0.5O₂/La_0.67Sr_0.33MnO₃ ferroelectric capacitors via the sensitivity of nanobeam X-ray diffraction experiments during application of electrical bias. We show that the virgin rhombohedral phase exhibits a negative linear piezoelectric effect with piezoelectric coefficient (d₃₃) ~ 0.5 to 0.8 pm/V. Above the coercive voltage, the piezoelectric coefficient is suppressed. For higher voltages, and with the onset of DC conductivity throughout the capacitor, a second-order effect is observed.

Investigating the electromechanical behavior of unconventionally ferroelectric Hf0.5Zr0.5O2-based capacitors through operando nanobeam X-ray diffraction

Investigating the electromechanical behavior of unconventionally ferroelectric Hf_0.5Zr_0.5O₂-based capacitors through operando nanobeam X-ray diffraction