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

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

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

Projekt

<a href="/cs/project/LM2023065" target="_blank" >LM2023065: Laboratoř pro syntézu a měření materiálů</a><br>

Návaznosti

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

Rok uplatnění

2024

Kód důvěrnosti údajů

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

Název periodika

Ceramics International

ISSN

0272-8842

e-ISSN

1873-3956

Svazek periodika

50

Číslo periodika v rámci svazku

19

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

9

Strana od-do

35657-35665

Kód UT WoS článku

001293441300001

EID výsledku v databázi Scopus

2-s2.0-85197544039