Fluorite-related iridate Pr 3 IrO 7 : crystal growth, structure, magnetism, thermodynamic, and optical properties.

Autor: Kumar H; Experimentalphysik II, Institute of Physics, Augsburg University, 86159 Augsburg, Germany., Köpf M; Experimentalphysik II, Institute of Physics, Augsburg University, 86159 Augsburg, Germany., Ullrich A; Experimentalphysik IV, Institute of Physics, Augsburg University, 86159 Augsburg, Germany., Klinger M; Experimentalphysik VI, Center of Electronic Correlations and Magnetism, Augsburg University, 86159 Augsburg, Germany., Jesche A; Experimentalphysik VI, Center of Electronic Correlations and Magnetism, Augsburg University, 86159 Augsburg, Germany., Kuntscher CA; Experimentalphysik II, Institute of Physics, Augsburg University, 86159 Augsburg, Germany.
Jazyk: angličtina
Zdroj: Journal of physics. Condensed matter : an Institute of Physics journal [J Phys Condens Matter] 2022 Oct 25; Vol. 34 (48). Date of Electronic Publication: 2022 Oct 25.
DOI: 10.1088/1361-648X/ac9a26
Abstrakt: Spin-orbit coupling in heavy 5 d metal oxides, in particular, iridates have received tremendous interest in recent years due to the realization of exotic electronic and magnetic phases. Here, we report the synthesis, structural, magnetic, thermodynamic, and optical properties of the ternary iridate Pr 3 IrO 7 . Single crystals of Pr 3 IrO 7 have been grown by the KF flux method. Structural analysis shows that Pr 3 IrO 7 crystallizes in an orthorhombic phase with Cmcm symmetry. The electron energy loss spectroscopy study indicates that Pr is in a 3+ valence state, which implies a 5+ oxidation state of Ir. Magnetization data measured at high and low magnetic fields do not exhibit any bifurcation between M ZFC and M FC , however, a weak hump in M ( T ) is observed atT∗∼10.4 K. The specific heat data reveal two maxima at ∼253 and ∼4.8 K. The optical conductivityσ1(ω)spectrum shows 24 infrared-active phonon modes and reveals an insulating behavior with an optical gapΔOPof size ∼500 meV. During cooling down, the temperature-dependent reflectivity spectrum reveals eight extra phonon modes below the structural phase transition (∼253 K). An anomaly is observed at aroundT∗in the temperature evolution of infrared-active mode frequencies suggesting the presence of significant spin-phonon coupling in the system.
(© 2022 IOP Publishing Ltd.)
Databáze: MEDLINE
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