AUTHOR=Cazorla Claudio , Ganduglia-Pirovano Maria VerĂ³nica , Carrasco Javier TITLE=Editorial: The Role of Non-stoichiometry in the Functional Properties of Oxide Materials JOURNAL=Frontiers in Chemistry VOLUME=7 YEAR=2019 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2019.00547 DOI=10.3389/fchem.2019.00547 ISSN=2296-2646