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تسجيل مستخدم جديدEmergent phase in short-periodic rare-earth nickelate superlattices
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Heterostructure engineering provides an efficient way to obtain several unconventional phases of LaNiO3, which is otherwise paramagnetic, metallic in bulk form. In this work, a new class of short periodic superlattices, consisting of LaNiO3 and EuNiO3 have been grown by pulsed laser interval deposition to investigate the effect of structural symmetry mismatch on the electronic and magnetic behaviors. Synchrotron based soft and hard X-ray resonant scattering experiments have found that these heterostructures undergo simultaneous electronic and magnetic transitions. Most importantly, LaNiO3 within these artificial structures exhibits a new antiferromagnetic, charge ordered insulating phase. This work demonstrates that emergent properties can be obtained by engineering structural symmetry mismatch across a heterointerface.
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The nature of the magnetic order in (La2/3Sr1/3MnO3)9/(LaNiO3)3 superlattices is investigated using x-ray resonant magnetic reflectometry. We observe a new c-axis magnetic helix state in the (LaNiO3)3 layers that had never been reported in nickelates
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Transition metal based oxide heterostructures exhibit diverse emergent phenomena e.g. two dimensional electron gas, superconductivity, non-collinear magnetic phase, ferroelectricity, polar vortices, topological Hall effect etc., which are absent in t
he constituent bulk oxides. The microscopic understandings of these properties in such nanometer thick materials are extremely challenging. Synchrotron x-ray based techniques such as x-ray diffraction, x-ray absorption spectroscopy (XAS), resonant x-ray scattering (RXS), resonant inelastic x-ray scattering (RIXS), x-ray photoemission spectroscopy, etc. are essential to elucidating the response of lattice, charge, orbital, and spin degrees of freedoms to the heterostructuring. As a prototypical case of complex behavior, rare-earth nickelates (RENiO3 with RE=La, Pr, Nd, Sm, Eu, Lu) based thin films and heterostructures have been investigated quite extensively in recent years. An extensive body of literature about these systems exists and for an overview of the field, we refer the interested readers to the recent reviews Annual Review of Materials Research 46, 305 (2016) and Reports on Progress in Physics 81, 046501 (2018). In the present article, we give a brief review that concentrates on the use of synchrotron based techniques to investigate a specific set of EuNiO3/LaNiO3 superlattices, specifically designed to solve a long-standing puzzle about the origin of simultaneous electronic, magnetic and structural transitions of the RENiO3 series.
The rare earth nickelates RNiO3 are metallic at high temperatures and insulating and magnetically ordered at low temperatures. The low temperature phase has been predicted to be type II multiferroic, i.e. ferroelectric and magnetic order are coupled
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