Iso-structural phase transition in pyrochlore iridates (Sm 1-x Bix)2Ir2O7 (x = 0, 0.02, and 0.10): high-pressure Raman and x-ray diffraction studies

Rosalin, M and Irshad, KA and Joseph, B and Telang, P and Singh, S and S Muthu, DV and Sood, AK (2024) Iso-structural phase transition in pyrochlore iridates (Sm 1-x Bix)2Ir2O7 (x = 0, 0.02, and 0.10): high-pressure Raman and x-ray diffraction studies. In: Journal of Physics Condensed Matter, 36 (45).

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Abstract

The pyrochlore iridates, A2Ir2O7, show a wide variety of structural, electronic, and magnetic properties controlled by the interplay of different exchange interactions, which can be tuned by external pressure. In this work, we report pressure-induced iso-structural phase transitions at ambient temperature using synchrotron-based x-ray diffraction (up to �20 GPa) and Raman-scattering measurements (up to �25 GPa) of the pyrochlore series (Sm 1-x Bix)2Ir2O7 (x = 0, 0.02, and 0.10). Our Raman and x-ray data suggest an iso-structural transition in Sm2Ir2O7 at P c � 11.2 GPa, associated with the rearrangement of IrO6 octahedra in the pyrochlore lattice. The transition pressure decreases to �10.2 and 9 GPa for x = 0.02 and 0.10, respectively. For all the samples, the linewidth of three phonons associated with Ir-O-Ir ( A 1 g and Eg) and Ir-O ( T 2 g 4 ) vibrations show anomalous decrease up to P c , due to decrease in electron-phonon interaction. © 2024 IOP Publishing Ltd

Item Type:	Journal Article
Publication:	Journal of Physics Condensed Matter
Publisher:	Institute of Physics
Additional Information:	The copyright for this article belongs to Institute of Physics.
Keywords:	Iridium compounds; Samarium compounds; X ray diffraction, Electronic and magnetic properties; External pressures; High pressure Raman; Isostructural transitions; Pyrochlore iridate; Pyrochlores; Raman Scattering measurements; Structural phase transition; X ray data; X-ray diffraction studies, Electron-phonon interactions, article; controlled study; electron; environmental temperature; human; hyperbaric pressure; phase transition; phonon; pressure; synchrotron; vibration; X ray diffraction
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	09 Sep 2024 10:28
Last Modified:	09 Sep 2024 10:28
URI:	http://eprints.iisc.ac.in/id/eprint/85956

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