Large spontaneous Hall effect in magnetic Weyl semimetallic Sm2Ir2 O7 (111) epitaxial thin films

Ghosh, M and Anil Kumar, PS (2023) Large spontaneous Hall effect in magnetic Weyl semimetallic Sm2Ir2 O7 (111) epitaxial thin films. In: Physical Review B, 108 (7).

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Abstract

Here, we present magnetotransport properties of Sm2Ir2O7 (111) single-crystalline epitaxial thin films grown with different strengths of compressive strain. A long-range magnetic ordering of Ir4+ moments is confirmed around the observed metal-semimetal transition. The low-temperature (2-20 K) resistivity data signify a gapless semimetallic charge transport. The high-temperature (above the transition) metallic part shows a non-Fermi-liquid behavior with a resistivity saturation, highlighting the importance of electron correlation in the 5d electron system. Magnetoresistance (MR) measurements for the applying field along the [111] direction suggest that at low temperatures (below 10 K), the all-in-all-out/all-out-all-in (AIAO/AOAI) spin structure is stable enough against the applied magnetic field. However, from 10 K onward, observation of a hysteretic MR implies that applying a magnetic field causes a change in the spin structure (from AIAO to three-out-one-in) and a plastic domain deformation. The Hall resistivity data show an anomalous/spontaneous Hall effect in the AIAO/AOAI antiferromagnetic phase. We have found that an epitaxial strain changes the sign as well as the magnitude of the anomalous Hall component, possibly by the modification of the electronic band dispersion and associated Berry curvature [ω(k□)]. Observation of an epitaxial strain-induced large spontaneous Hall effect (∼50μω cm, at 7 K) identifies the presence of Weyl points and the Weyl semimetallic phase of Sm2Ir2O7. It highlights the role of epitaxial strain in discovering new topological phases. These findings deepen our understanding of the anomalous Hall effect in Sm2Ir2O7 and provide a practical tuning knob to manipulate the Berry curvature and related topological properties in a wide range of quantum materials. © 2023 American Physical Society.

Item Type:	Journal Article
Publication:	Physical Review B
Publisher:	American Physical Society
Additional Information:	The copyright for this article belongs to the American Physical Society.
Keywords:	Antiferromagnetism; Binary alloys; Epitaxial growth; Fermi liquids; Fruits; Magnetoresistance; Spin Hall effect; Temperature; Thin films, Compressive strain; Epitaxial strain; Epitaxial thin films; Long range magnetic order; Lows-temperatures; Magneto transport properties; Resistivity data; Semimetallics; Single-crystalline; Spin structures, Topology
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	07 Nov 2023 11:04
Last Modified:	07 Nov 2023 11:04
URI:	https://eprints.iisc.ac.in/id/eprint/83039

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