Robustness of the pyrochlore structure in rare-earth A2Ir2O7 iridates and pressure-induced structural transformation in IrO2

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F24%3A10483556" target="_blank" >RIV/00216208:11320/24:10483556 - isvavai.cz</a>

Result on the web

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

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.ceramint.2024.06.383" target="_blank" >10.1016/j.ceramint.2024.06.383</a>

Result language

angličtina

Original language name

Robustness of the pyrochlore structure in rare-earth A2Ir2O7 iridates and pressure-induced structural transformation in IrO2

Original language description

A comprehensive study of the structural properties of the heavily investigated rare-earth A2Ir2O7 iridate series under extreme conditions is presented. From Pr2Ir2O7 to Lu2Ir2O7, the series is sufficiently covered by iridates with A = Pr, Sm, Dy, Ho, Er, Tm, Yb, and Lu; general trends and systematics within the series, including the understudied heavy-rare-earth members, are dependably followed. Temperature- and pressure-dependent synchrotron X-ray powder diffraction experiments reveal robustness of the pyrochlore structure throughout the series, down to 4 K and up to 20 GPa. The thermal expansivity of the pyrochlore lattice is determined, all falling in the Debye temperature range of theta D = 360-420 K. The pressure compressibility shows a systematic increase of the bulk modulus with the rare-earth atomic number from K = 180-210 GPa. Combining the results of thermal measurements (Debye temperature) and pressure measurements (bulk modulus) enables us to determine the Gr &amp; uuml;neisen parameter of selected members and compare it to previous studies. Temperature and pressure evolution of the fractional coordinate of oxygen at 48f Wyckoff position, the sole free fractional coordinate in the crystal structure, is investigated and discussed regarding the antiferromagnetic ordering of the Ir magnetic moments. In addition to results on A2Ir2O7 iridates, the temperature and pressure evolution of the crystal structure of an IrO2 minority phase is followed. The tetragonal rutile-type structure is stable down to the lowest temperature. However, an application of pressure of approximately 15 GPa induces a structural transition: The tetragonal structure is orthorhombically distorted. The orthorhombic structure is still not fully stabilised at 20 GPa, and further distortion of the lattice (or subsequent structural transformations) is expected with increasing external pressure.

Czech name

—

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

—

OECD FORD branch

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Project

<a href="/en/project/LM2023065" target="_blank" >LM2023065: Material growth and measurement laboratory</a><br>

Continuities

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

Publication year

2024

Confidentiality

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

Name of the periodical

Ceramics International

ISSN

0272-8842

e-ISSN

1873-3956

Volume of the periodical

50

Issue of the periodical within the volume

19

Country of publishing house

GB - UNITED KINGDOM

Number of pages

9

Pages from-to

35657-35665

UT code for WoS article

001293441300001

EID of the result in the Scopus database

2-s2.0-85197544039