I10-Beamline for Advanced Dichroism - scattering
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Duncan
Miertschin
,
Sundar
Kunwar
,
Balaram
Regmi
,
Poshan
Kandel
,
Sanjib
Thapa
,
Davis
Crater
,
Luca
Basso
,
Adam
Dodson
,
Zheng
Gai
,
Lide
Yao
,
Yu-Wei
Chen
,
Peter
Bencok
,
Armin
Kleibert
,
Yen-Lin
Huang
,
Andy
Mounce
,
Paul G.
Kotula
,
Sebastiaan
Van Dijken
,
Alessandro R.
Mazza
,
Thomas Z.
Ward
,
Nick
Shepelin
,
Alan
Farhan
Diamond Proposal Number(s):
[40992]
Open Access
Abstract: Multiferroics that combine ferroelectricity and magnetic order are attractive for electronic and spintronic technologies, yet chemical disorder that promotes relaxor ferroelectricity usually suppresses long-range magnetic order. Here, we report entropy-stabilized relaxor multiferroicity in epitaxial hexagonal (Tb0.2Dy0.2Ho0.2Lu0.2Yb0.2)FeO3 thin films. Structural, magnetic, dielectric, and synchrotron spectroscopic measurements show the coexistence of relaxor ferroelectricity and long-range ferromagnetic order. We find that improper ferroelectricity remains robust against A-site configurational disorder, while the Fe sublattice preserves magnetic exchange. This separation of the microscopic origins of the polar and magnetic responses enables chemically disordered multiferroicity. Our results establish entropy engineering in hexagonal ferrites as a route toward multifunctional oxide thin films and provide a general design strategy for high-entropy multiferroics.
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Sep 2026
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M.
Ghidini
,
Sergio
Valencia
,
A.
Lesaine
,
R.
Mansell
,
V.
Farenkov
,
X.
Moya
,
N. A.
Stelmashenko
,
F.
Maccherozzi
,
C. W. H.
Barnes
,
F.
Kronast
,
S. S.
Dhesi
,
N. D.
Mathur
Open Access
Abstract: Voltage control of magnetic states in multiferroic heterostructures represents a promising route toward voltage-programmable magnetic devices. However, it remains challenging to achieve deterministic and non-volatile electrical control of well-defined magnetic states without the assistance of a magnetic field. Here we demonstrate repeatable and non-volatile voltage-driven interconversion between giant single-domain and multidomain magnetic states in a strain-coupled heterostructure comprising permalloy (Py) and 0.68Pb(Mg1/3Nb2/3)O3–0.32PbTiO3 (011)pc (PMN-PT) (pc = pseudocubic). Growth-induced in-plane uniaxial magnetic anisotropy yields a square hysteresis loop, indicating a remanent monodomain state that is consistent with 15 µm-diameter XMCD-PEEM images. Low-voltage biasing of the PMN-PT substrate repeatably induces a ∼90° in-plane rotation of the magnetic easy axis and the concomitant formation of a multidomain state. At higher voltages, the easy axis rotates back to its original orientation, restoring the monodomain state. Cycling the ferroelectric substrate through minor loops near the coercive field yields non-volatile and repeatable switching between the multidomain and monodomain states. These results provide a pathway for voltage-programmable engineering of magnetic single-domain states in multiferroic heterostructures.
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Aug 2026
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Pratap
Pal
,
Xiaoxi
Deng
,
Gi‐yeop
Kim
,
Kyoungjun
Lee
,
Jheng-Cyuan
Lin
,
Prithwijit
Mandal
,
Jiangfeng
Yang
,
Paul
Steadman
,
Pascal
Manuel
,
Roger D.
Johnson
,
Si-Young
Choi
,
Paolo G.
Radaelli
,
Chang-Beom
Eom
Open Access
Abstract: The spin cycloid characteristic of noncollinear antiferromagnets offers significant potential for energy-efficient, magnon-mediated spintronic applications. Multiferroic BiFeO3 is among the most promising candidate materials because its antiferromagnetic order can be controlled by an electric field. However, in epitaxial BiFeO3 thin films, substrate clamping and epitaxial strain modify the cycloidal magnetic structure while limiting efficient ferroelastic-ferroelectric switching. Here, we show that strain-released freestanding BiFeO3 membranes overcome these limitations. Compared with substrate-clamped epitaxial thin films, a 100-nm-thick freestanding membrane exhibits ≈50% faster electric-field-driven ferroelectric switching and a spatially uniform, bulk-like single spin cycloid, as revealed by resonant elastic X-ray scattering. In contrast, the epitaxial thin film exhibits an expanded cycloid periodicity and slower ferroelectric switching dynamics, reflecting the influence of substrate-induced strain. Freestanding BiFeO3 membranes therefore overcome substrate-induced constraints by simultaneously restoring the intrinsic bulk-like spin cycloid and enabling substantially faster ferroelectric switching. This combination of robust noncollinear antiferromagnetic order and efficient electric-field switching establishes freestanding BiFeO3 membranes as a promising magnetoelectric platform for low-power magnonic and spintronic technologies, while enabling heterogeneous integration with Si-based devices.
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Aug 2026
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I21-Resonant Inelastic X-ray Scattering (RIXS)
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Xiaoyang
Chen
,
Wenliang
Zhang
,
Fei
Peng
,
Ting
Cui
,
Guangdi
Zhou
,
Zezhong
Li
,
Jaewon
Choi
,
Lizhi
Xu
,
Yiu-Fung
Chiu
,
Stefano
Agrestini
,
Sahil
Tippireddy
,
Haoliang
Huang
,
Heng
Wang
,
Xianfeng
Wu
,
Peng
Li
,
Jin-Feng
Jia
,
Mirian
Garcia-Fernandez
,
Yi
Lu
,
Er-Jia
Guo
,
Qi-Kun
Xue
,
Zhuoyu
Chen
,
Donglai
Feng
,
Ke-Jin
Zhou
Diamond Proposal Number(s):
[42637]
Open Access
Abstract: The recent discovery of Ruddlesden-Popper (RP) nickelate thin-film superconductors has opened a new frontier in unconventional superconductivity. Its realization requires both compressive epitaxial strain and highly oxidative growth conditions, yet the microscopic pathway from the parent phase to the superconducting phase remains elusive. Here, X-ray absorption spectra and resonant inelastic X-ray scattering are employed to track this evolution by independently tuning strain and oxygen content in (La,Pr)3Ni2O7 − δ thin films. We uncover a remarkable two-step narrative. First, signatures of delocalization emerge: Spectral weight transfers from a “Upper Hubbard”-like peak to the hole-like peak associated with O 2pz state, and in parallel, the initially localized Ni
orbital becomes more itinerant followed by the broadening and weakening of dd orbital excitations. Second, as itinerancy increases, long-range spin-density-wave (SDW) order is suppressed in both intensity and correlation length, indicating direct competition with superconductivity. Yet, short-range magnons persist: they become damped but their bandwidth stays unchanged. Our results paint a coherent picture that both strain and oxygenation drive the RP bilayer nickelates towards the superconducting instability, where the O 2pz and Ni
orbitals become delocalized. Concomitantly, the long-range magnetic order loses coherence and gets suppressed. These findings establish an orbital-selective route to RP nickelate superconductivity, in which the emergence and progressive delocalization of the interlayer
-2pz-
channel and the robust short-range magnons upon the melting of SDW order are prerequisites, providing strong constraints for theory and the roadmap for designing nickelate superconductors.
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Aug 2026
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I05-ARPES
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Cong
Li
,
Zhilong
Yang
,
Hongxiong
Liu
,
Magnus H.
Berntsen
,
Francesco
Scali
,
Dibya
Phuyal
,
Jianfeng
Zhang
,
Timur K.
Kim
,
Jacek
Osiecki
,
Balasubramanian
Thiagarajan
,
Youguo
Shi
,
Tao
Xiang
,
Quansheng
Wu
,
Oscar
Tjernberg
Diamond Proposal Number(s):
[39652, 41048]
Open Access
Abstract: Topological materials are defined by the correspondence between bulk topology and boundary states, yet this correspondence becomes enigmatic on low-symmetry surfaces where bulk and surface periodicities may not coincide within a conventional first bulk Brillouin zone projection. Here we study the (103) surface of the Weyl semimetal NdAlSi and identify Fermi arc interference in the boundary spectrum. Angle-resolved photoemission spectroscopy uncovers loop-like Fermi-arc connectivity and characteristic replica modulations that are not observed on high symmetry surfaces. Crucially, the topological surface states themselves are reconstructed because Fermi arcs from phase-shifted bulk-zone projections overlap and hybridize, producing connectivity patterns unique to low-symmetry facets. We show that these emerge from incomplete bulk projection and multi-cell interference governed by a least-common-multiple framework. Least-common-multiple guided density functional theory and Green’s-function calculations reproduce the reconstructed periodicity and dominant replica structure in the spectra, providing a broadly applicable commensuration guideline. These findings resolve the apparent bulk-boundary correspondence paradox on low-symmetry surfaces and provide an operational route to model and interpret boundary spectra on complex facets.
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Aug 2026
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I10-Beamline for Advanced Dichroism - scattering
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Diamond Proposal Number(s):
[8703, 9117, 9595]
Open Access
Abstract: Magnetic skyrmions are spin textures with nontrivial topology that form two-dimensional hexagonal lattices (SkX) in chiral magnets. Element-specific reciprocal-space characterization of skyrmion lattices with soft x-rays commonly relies on transmission geometries, which require thinning of bulk crystals and can modify their magnetic properties. Here, we show that resonant elastic x-ray scattering in a grazing-incidence geometry (GIREXS) provides a nondestructive and geometrically flexible probe of skyrmion lattices in bulk materials. Using MnSi as a model system, GIREXS resolves the helical, conical, and skyrmion-lattice states through their characteristic magnetic satellite peaks and yields the skyrmion wave vector. By operating just above the critical angle (𝛼c≈1.6° in MnSi at the Mn 𝐿3 edge), the method achieves a probing depth of approximately 3 nm, tunable up to approximately 20 nm via the incidence angle, while maintaining full reciprocal-space access to the in-plane magnetic correlations. The grazing-incidence approach circumvents the structural Bragg-peak constraints that limit conventional reflection resonant elastic x-ray scattering (REXS) at fixed soft-x-ray energies. Our measurements establish GIREXS as a practical method for studying magnetic superstructures in bulk crystals, providing direct reciprocal-space access to magnetic satellite reflections and a basis for future depth-controlled, element-selective investigations of complex spin textures.
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Aug 2026
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Yidian
Li
,
Mingxin
Zhang
,
Xian
Du
,
Cuiying
Pei
,
Jieyi
Liu
,
Houke
Chen
,
Wenxuan
Zhao
,
Kaiyi
Zhai
,
Yinqi
Hu
,
Senyao
Zhang
,
Jiawei
Shao
,
Mingxin
Mao
,
Yantao
Cao
,
Jinkui
Zhao
,
Zhengtai
Liu
,
Dawei
Shen
,
Yaobo
Huang
,
Makoto
Hashimoto
,
Donghui
Lu
,
Zhongkai
Liu
,
Yulin
Chen
,
Hanjie
Guo
,
Yilin
Wang
,
Yanpeng
Qi
,
Lexian
Yang
Abstract: The interplay among orbital-selective electron correlation, Hund's coupling, tunable structural motifs, and Kondo-like scattering establishes a compelling paradigm for understanding and engineering correlated multiorbital systems, as vividly exemplified by nickelate superconductors. Here, using high-resolution angle-resolved photoemission spectroscopy combined with theoretical calculations, we systematically investigate the electronic properties of trilayer nickelates. In La4Ni3O10, we observe pronounced interorbital hybridization, whereas in Pr4Ni3O10, the flat 𝑑𝑧2 band becomes markedly incoherent and diminishes in spectral weight. By contrast, the dispersive 𝑑𝑥2−𝑦2 bands retain coherence in both compounds. This striking incoherence/coherence dichotomy identifies an orbital differentiation modulated by the interlayer Ni-O-Ni bonding angle. The depletion of the 𝑑𝑧2 orbitals further suppresses the interorbital hybridization and influences the density-wave transition in Pr4Ni3O10. Moreover, the density-wave gap is substantially reduced in Pr4Ni3O10, likely due to extra scattering channels provided by the local moments of Pr3+ cations. Our findings reveal a structural control parameter for the multiorbital correlated state in trilayer nickelates, providing important insights into the emergence of superconductivity under high pressure.
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Aug 2026
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I10-Beamline for Advanced Dichroism - scattering
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Moritz
Winter
,
A.
Pignedoli
,
M. C.
Rahn
,
A. S.
Sukhanov
,
B.
Achinuq
,
J. R.
Bollard
,
M.
Azhar
,
K.
Everschor-Sitte
,
D.
Pohl
,
S.
Schneider
,
A.
Tahn
,
V.
Ukleev
,
M.
Valvidares
,
A.
Thomas
,
D.
Wolf
,
P.
Vir
,
T.
Helm
,
G.
Van Der Laan
,
T.
Hesjedal
,
J.
Geck
,
C.
Felser
,
B.
Rellinghaus
Diamond Proposal Number(s):
[28882]
Open Access
Abstract: Chiral soliton lattices (CSLs) emerge from the competition between Dzyaloshinskii–Moriya interaction, anisotropy, and magnetic fields. While well established in monoaxial helimagnets, their role in materials with anisotropic, direction-dependent chirality remains poorly understood. Here, we report the direct observation of a crossover from π to 2π soliton lattices in the non-centrosymmetric Heusler compound Mn1.4PtSn. Combining Lorentz transmission electron microscopy, resonant elastic X-ray scattering, and micromagnetic simulations, we identify a π-CSL as the magnetic ground state—rather than the expected spiral phase—which evolves into a classical 2π-CSL under increasing out-of-plane fields. This transition is governed by an interplay between uniaxial magnetocrystalline anisotropy and magnetostatic interactions, qualitatively captured by a double sine-Gordon model. Our framework extends to materials with D2d, S4, Cnv, or Cn symmetries in the thin-film limit, providing a unifying route to engineer magnetic phase diagrams in chiral systems with implications for soliton-based spintronics and topological transport.
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Aug 2026
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[32893, 39378]
Open Access
Abstract: Systematic strategies to design properties such as ferroelectricity or magnetoelectric coupling are well-established in simple perovskite materials, but they remain scarce in more complex framework structures. Using a hexagonal polytype of the ternary Manganite AMnO3 (A= Ba, Sr, Ca) as a model system, we introduce a symmetry-guided design principle in which an inversion-breaking rigid-unit mode (RUM) serves as a single structural instability generating both polar and ferromagnetic orders within a bulk antiferromagnetic material. Symmetry analysis and first-principles calculations reveal that cooperative tilts of the Mn2O9 bioctahedral dimers generate a spontaneous polarization, and in the antiferromagnetically ordered state, they also induce a ferromagnetic moment. High-resolution diffraction and magnetic susceptibility measurements show that the structural and magnetic orders persist as high as 450 and 280 K, respectively, highlighting the untapped potential of framework structures that deviate from simple perovskite motifs to be designed to host useful ferroic properties. Our approach establishes a transferable symmetry-based framework for engineering ferroelectric and magnetoelectric states across chemically diverse framework architectures.
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Aug 2026
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I15-Extreme Conditions
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Nikolaos
Kelaidis
,
Panagiotis
Mangelis
,
Nikolaos
Moutzouris
,
Ioannis
Koutselas
,
Nagia S.
Tagiara
,
Savvas
Hadjipanteli
,
Emmanuel
Klontzas
,
Dominik
Daisenberger
,
Panagiotis
Oikonomopoulos
,
Theodora
Kyratsi
,
Andreas
Kaltzoglou
Diamond Proposal Number(s):
[37935]
Abstract: Semiconducting clathrates is a class of inclusion compounds with potential application in the field of thermoelectricity. It is known that the type-I clathrate Cs8Sn44□2 crystallizes at room temperature in the cubic space group Ia-3d (No. 230) with high ordering of the two Sn vacancies (□) in the host framework whereas above 363 K it converts to the disordered modification (space group Pm-3n, No. 223) with lower ordering of the vacancies. In the current study, high-pressure X-ray synchrotron diffraction experiments show that this clathrate structure converts upon compression to the disordered modification and also exhibits a bulk modulus of 55.4 GPa. Differential scanning calorimetry determines that the reversibility of the order-disorder phase transition depends largely on the heating-cooling rate. The hot-pressed Cs8Sn44 pellet behaves as an n-type semiconductor with a band gap of 0.33 eV and a maximum power factor of 3.56 μW cm-1 K-2 at 473 K, whereas at higher temperatures it degrades irreversibly into β-Sn, as also confirmed by Raman spectroscopy. First-principles calculations based on density functional theory were combined with Boltzmann transport theory to investigate the bulk modulus and the electron-transport properties of Cs8Sn44 using the constant relaxation time approximation. The computational results show that the electronic properties depend largely on the doping concentrations.
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Aug 2026
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