Topotactic Reduction-Induced Stabilization of β-La2Mo2O8.68 Phase: Structure, Static Oxygen Disorder, and Electrical Properties
Year: 2024
Type: article
Abstract: La 2 Mo 2 O 9 is acknowledged as an exceptional oxide ion conductor. It undergoes a reversible phase transition around 580 °C from the nonconductive low-temperature monoclinic α-La 2 Mo 2 O 9 phase to the highly conductive high-temperature cubic β-La 2 Mo 2 O 9 phase. In addition, La 2 Mo 2 O 9 demonstrates complex chemistry under reducing conditions. This study reports, for the first time, the stabilization at ambient temperature of a novel cubic phase through a topotactic reduction of α-La 2 Mo 2 O 9 employing CaH 2 . This phase contains approximately ∼3 atom % oxygen vacancies relative to the nominal composition (La 2 Mo 2 O 8.68(1) ). The cubic symmetry is associated with a static distribution of these vacancies, in contrast to the dynamic distribution observed in the high-temperature cubic β-La 2 Mo 2 O 9 phase reported previously. Additionally, the material exhibits mixed-ion-electronic conduction, which expands its potential use in applications requiring both ionic and electronic transport.
Source: Inorganic Chemistry
Institutions: Guilin University of Technology, Université d'Orléans, Centre National de la Recherche Scientifique, Conditions Extrêmes et Matériaux Haute Température et Irradiation, Oak Ridge National Laboratory, Guangxi Key Laboratory of Electrochemical and Magnetochemical Functional Materials, Consejo Superior de Investigaciones Científicas, Instituto de Ciencia de Materiales de Sevilla, Le Studium, Universidad de Sevilla
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4404517463