Oxygen Vacancies in Perovskite Oxide Piezoelectrics

The excellent electro-mechanical properties of perovskite oxide ferroelectrics make these materials major piezoelectrics. Oxygen vacancies are believed to easily form, migrate, and strongly affect ferroelectric behavior and, consequently, the piezoelectric performance of these materials and devices based thereon. Mobile oxygen vacancies were proposed to explain high-temperature chemical reactions half a century ago. Today the chemistry-enabled concept of mobile oxygen vacancies has been extrapolated to arbitrary physical conditions and numerous effects and is widely accepted. Here, this popular concept is questioned. The concept is shown to conflict with our modern physical understanding of ferroelectrics. Basic electronic processes known from mature semiconductor physics are demonstrated to explain the key observations that are groundlessly ascribed to mobile oxygen vacancies. The concept of mobile oxygen vacancies is concluded to be misleading.

Authors:
Tyunina Marina

Publication type:
A1 Journal article – refereed

Place of publication:

Keywords:
electronic, ferroelectric, oxygen vacancy, perovskite oxide, semiconductor

Published:

Full citation:
Tyunina, M. Oxygen Vacancies in Perovskite Oxide Piezoelectrics. Materials 2020, 13, 5596. https://doi.org/10.3390/ma13245596

DOI:
https://doi.org/10.3390/ma13245596

Read the publication here:
http://urn.fi/urn:nbn:fi-fe202102124597