Pressure-Induced Charge Disorder-Order Transition in the Cs4O6 Sesquioxide

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F20%3A10411115" target="_blank" >RIV/00216208:11320/20:10411115 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=.rIPaqgiHc" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=.rIPaqgiHc</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.inorgchem.9b02974" target="_blank" >10.1021/acs.inorgchem.9b02974</a>

Result language

angličtina

Original language name

Pressure-Induced Charge Disorder-Order Transition in the Cs4O6 Sesquioxide

Original language description

Cs4O6 adopts two distinct crystal structures at ambient pressure. At temperatures below similar to 200 K, its ground state structure is tetragonal, incorporating two symmetry-distinct dioxygen anions, diamagnetic peroxide, O-2(2-), and paramagnetic superoxide, O-2(-), units in a 1:2 ratio, consistent with the presence of charge and orbital order. At high temperatures, its ground state structure is cubic, comprising symmetry-equivalent dioxygen units with an average oxidation state of -4/3, consistent with the adoption of a charge-disordered state. The pressure dependence of the structure of solid Cs4O6 at 300 K and at 13.4 K was followed up to similar to 12 GPa by synchrotron X-ray powder diffraction. When a pressure of similar to 2 GPa is reached at ambient temperature, an incomplete phase transition that is accompanied by a significant volume reduction (similar to 2%) to a more densely packed highly anisotropic tetragonal structure, isostructural with the low-temperature ambient-pressure phase of Cs4O6, is encountered. A complete transformation of the cubic (charge-disordered) to the tetragonal (charge-ordered) phase of Cs4O6 is achieved when the hydrostatic pressure exceeds 6 GPa. In contrast, the pressure response of the Cs4O6 cubic/tetragonal phase assemblage at 13.4 K is distinctly different with the cubic and tetragonal phases coexisting over the entire pressure range (to similar to 12 GPa) accessed in the present experiments and with only a small fraction of the cubic phase converting to tetragonal. Pressure turns out to be an inefficient stimulus to drive the charge disorder-order transition in Cs4O6 at cryogenic temperatures, presumably due to the high activation barriers (much larger than the thermal energy at 13.4 K) associated with the severe steric hindrance for a rotation of the molecular oxygen units necessitated in the course of the structural transformation.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10402 - Inorganic and nuclear chemistry

Project

<a href="/en/project/EF15_003%2F0000487" target="_blank" >EF15_003/0000487: Physics of martensitic transformation for functionality enhancement of crystalline materials and nanostructures</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Inorganic Chemistry

ISSN

0020-1669

e-ISSN

—

Volume of the periodical

59

Issue of the periodical within the volume

2

Country of publishing house

US - UNITED STATES

Number of pages

9

Pages from-to

1256-1264

UT code for WoS article

000509420100036

EID of the result in the Scopus database

2-s2.0-85078371123