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428 items found (0 items not approved), displaying 1 to 10.[First/Prev] 1, 2, 3, 4, 5, 6, 7, 8 [Next/Last]

Instruments / Technical Area	Publication Details	Published
B07-B1-Versatile Soft X-ray beamline: High Throughput ES1	X-ray and ion-beam reduction kinetics of mixed metal oxides as an informative tool Fatima Sajid , Charalampos Drivas , Emila Duka , Hanna Bras-Genfoud , Arthur Graf , Merlin Liedtke , David J. Morgan , Robert Palgrave , Christopher M. A. Parlett , Emily Worobiej , Mark A. Isaacs Acs Applied Materials & Interfaces 8 DOI: 10.1021/acsami.6c07564 Diamond Proposal Number(s): [40403, 29271] Open Access Show Abstract ▼ Abstract: Ion beams have long served as indispensable tools in surface science for layer removal and depth profiling, yet their aggressive nature often limits use to inorganic systems due to radiation-induced chemical damage. Here, we revisit this “limitation” as an opportunity to explore whether ion beams can purposefully induce redox transformations that reveal chemical and structural information inaccessible by conventional means. Using a suite of mixed metal oxides (Ce–Mo, Ni/Co–Mo, and Ce–Ti), we demonstrate that ion beam exposure can drive controlled reduction processes that sensitively report on intrinsic redox stability and metal–oxygen bonding and provide an alternative route by which to assess relative chemical and electronic changes, to otherwise costly and time-consuming synchrotron studies.	Aug 2026
I16-Materials and Magnetism	Collinear spin density wave state in distorted square-lattice GdNiSn4 Charles C. Tam , Sarah Schwarz , Xin Zhang , Sudipta Chatterjee , Scott B. Lee , Rebecca Scatena , Leslie M. Schoop , Stephen Wilson Physical Review Materials 10 DOI: 10.1103/2plq-5mql Diamond Proposal Number(s): [39446] Show Abstract ▼ Abstract: We characterize the magnetic ground state of the newly synthesized lanthanide intermetallic GdNiSn4via resonant elastic x-ray scattering measurements. This compound forms distorted square nets of Gd that initially order magnetically below 23 K, followed by a lower-temperature transition at 16 K. Our scattering data identify the ground state order as a single-q incommensurate, collinear order that slides towards a commensurate wave vector above the 16 K transition. Magnetic symmetry analysis combined with azimuthal dependence resolves the ground state magnetic structure as a moment-modulated spin density wave state with Gd moments oriented parallel to the in-plane 𝑎-axis. We discuss connections between the observed magnetic order and electronic properties in this square-net compound.	Jul 2026
I05-ARPES	Superconducting coherence boosted by outer-layer metallic screening in multilayered cuprates Junhyeok Jeong , Kifu Kurokawa , Shiro Sakai , Tomotaka Nakayama , Kotaro Ando , Naoshi Ogane , Soonsang Huh , Matthew D. Watson , Timur K. Kim , Cephise Cacho , Chun Lin , Makoto Hashimoto , Donghui Lu , Takami Tohyama , Kazuyasu Tokiwa , Takeshi Kondo Nature Communications DOI: 10.1038/s41467-026-75295-z Diamond Proposal Number(s): [36822, 30646, 28930, 25416] Open Access Show Abstract ▼ Abstract: In multilayered high-Tc cuprates, the inner CuO2 planes (IPs) are spatially separated from dopant layers and thus remain cleaner than the outer planes (OPs). Here, we investigate five-layer (Cu,C)Ba2Ca4Cu5Oy (Cu1245) and three-layer Ba2Ca2Cu3O6(F,O)2 (F0223) using angle-resolved photoemission spectroscopy (ARPES) and uncover an unprecedented situation, in which only the IPs become superconducting while the OPs remain metallic at low temperatures. Our model calculations indicate that over 95% of the OP wavefunction remains confined to OP itself, rendering superconducting proximity negligible. This interlayer decoupling realizes an ideal configuration—a single superconducting CuO2 layer screened from the dopant layer-induced disorder by heavily overdoped metallic OPs. The clean CuO2 layer exhibits a large superconducting gap with coherent Bogoliubov peaks extending beyond the antiferromagnetic zone boundary, and a widely extended coherent flat band at the Brillouin zone edge. These findings introduce the “degree of screening” as a physical parameter for probing competition between pseudogap and superconductivity, and for bridging typically disordered real materials with the idealized theoretical models.	Jul 2026
I15-Extreme Conditions	Pressure-induced structural phase transitions in heavy metal hydrides Hannah A. Shuttleworth DOI: 10.7488/era/7303 Show Abstract ▼ Abstract: Pressure is an important thermodynamic variable that can manipulate interatomic distances and electronic band structures of materials. One can induce phase transitions by experimentally varying pressure-temperature conditions, revealing exotic properties and structures that cannot be attained under ambient conditions. The study of binary metal hydrides has garnered significant attention over the past decade due to their diverse physical and chemical behaviours. At sufficiently high pressures, the chemical potential of hydrogen increases and may eventually overcome the dissociation barrier at the surface of a metal, forming metal alloys with atomic hydrogen occupying interstitial sites. These metal hydrides have been demonstrated to exhibit remarkable phenomena such as superionicity, hydrogen storage potential and conventional high-temperature superconductivity. Currently, there exists a plethora of theoretical calculations predicting novel stoichiometries, structures and electronic states of various binary metal-hydrogen systems. More recently, theoretical work has gradually moved towards predictions in ternary and even quaternary systems. Despite this, there is still much to learn from binary hydrides, such as how hydrogen content affects electronic properties in specific systems and how the addition of f -electrons may influence superconducting transitions. This PhD thesis covers a total of five highpressure binary heavy metal hydride systems extensively studied in diamond anvil cell experiments. Firstly, the pressure-induced metallisation of BaH2 and the effect of hydrogenation are presented, followed by studies that reveal complexity and distinct structural analogies of novel heavy lanthanide polyhydrides up to 180 GPa (namely ytterbium, thulium, and erbium hydrides). Finally, structural phase transitions, recoverability and predicted superconductivity are explored in the uranium-hydrogen system below 100 GPa.	Jun 2026
B07-B1-Versatile Soft X-ray beamline: High Throughput ES1 B07-C-Versatile Soft X-ray beamline: Ambient Pressure XPS and NEXAFS	Interfacial control of orbital occupancy and spin state in LaCoO3 Ellen M. Kiens , Nicolas Gauquelin , Arno Annys , Emma Van Der Minne , Iris C. G. Van Den Bosch , Matthijs A. Van Spronsen , Zezhong Zhang , Annick De Backer , Sandra Van Aert , Jo Verbeeck , Gertjan Koster , Bastian Mei , Frank M. F. De Groot , Christoph Baeumer Physical Review Materials 10 DOI: 10.1103/kxnn-w1rk Diamond Proposal Number(s): [33107, 31118] Show Abstract ▼ Abstract: Transition metal oxides exhibit a wide range of tunable electronic properties arising from the complex interplay of charge, spin, and lattice degrees of freedom, governed by their 𝑑 orbital configurations, making them particularly interesting for oxide electronics and (electro)catalysis. Perovskite oxide heterointerfaces offer a promising route to engineer these orbital states. In this work, we tune the Co3⁢𝑑 orbital occupancy in LaCoO3 from a partial 𝑑7 to a partial 𝑑5 state through interfacial engineering with LaTiO3, LaMnO3, LaAlO3, and LaNiO3. Using x-ray absorption spectroscopy combined with charge transfer multiplet calculations, we identify differences in the Co valence and spin state for the series of oxide heterostructures. LaTiO3 and LaMnO3 interfaces result in interfacial charge transfer towards LaCoO3, resulting in a partial 𝑑7 orbital occupancy, while a LaNiO3 interface results in a partial Co 𝑑5 occupancy. Strikingly, a LaAlO3 spacer layer between LaNiO3 and LaCoO3 results in a Co 𝑑6 low-spin state. These results indicate that the Co spin state, like the valence state, is governed by the interfacial environment. High-resolution scanning transmission electron microscopy imaging reveals a clear connection between strain and spin configuration, emphasizing the importance of structural control at oxide interfaces. Overall, this work demonstrates that interfacial engineering simultaneously governs orbital occupancy and spin state in correlated oxides, advancing spin-engineering strategies in correlated oxides and offering new insights for the rational design of functional oxide heterostructures.	Jun 2026
I05-ARPES	Pressure-driven metal-insulator transition in BaMn2P2: A correlated Mn-pnictide analog of Fe-based superconductors Youngro Lee , Daniil V. Evtushynsky , Richard Gaal , Igor Morozov , Anita Maksutova , Tomasz Poreba , Timur Kim , Henrik M. Ronnow Physical Review B 113 DOI: 10.1103/k8zt-mkyk Diamond Proposal Number(s): [28484, 31262] Open Access Show Abstract ▼ Abstract: We report pressure-induced metallization in BaMn2P2 based on resistivity measurements in a diamond anvil cell. At ambient pressure, the temperature-dependent resistivity is well described by a two-gap Arrhenius model, yielding intrinsic and extrinsic activation energies of approximately 0.2 and 0.04 eV, respectively. Angle-resolved photoemission spectroscopy (ARPES) shows no detectable spectral weight at the Fermi level within the measured momentum window. The growth of spectral weight at higher binding energies is consistent with the energy scales inferred from transport measurements. Under pressure, the temperature dependence of the resistivity evolves from insulatinglike to mixed-slope behavior and becomes metallic above Pc ≈ 7 GPa, with no low-temperature upturn. The resistivity ratio R(P) = ρ(100 K)/ρ(300 K) also drops abruptly near Pc. A baseline transport model combining Bloch-Grüneisen phonon scattering with a thermally activated carrier density fails to reproduce this sharp change for any smoothly varying activation energy. Temperature- and pressure-dependent x-ray diffraction shows smooth evolution of V with no symmetry change and no resolvable discontinuity at Pc . Taken together, these results indicate an abrupt pressure-driven metallization near Pc, with no evidence for a structural phase transition within our experimental resolution.	May 2026
I21-Resonant Inelastic X-ray Scattering (RIXS)	Doping evolution of the charge density wave and charge density fluctuations in La2-xSrxCuO4 Charles C. Tam , Mengze Zhu , Maud C. Barthélemy , Lauren J. Cane , Oliver J. Lipscombe , Stefano Agrestini , Jaewon Choi , Mirian Garcia-Fernandez , Ke-Jin Zhou , Stephen M. Hayden Physical Review B 113 DOI: 10.1103/6hcs-2y4y Diamond Proposal Number(s): [29150] Open Access Show Abstract ▼ Abstract: Cuprate superconductors show various collective charge correlations that are intimately connected with their electronic properties. In particular, charge order in the form of an incommensurate charge density wave (CDW) order with an in-plane wave vector 𝛿CDW≈0.23–0.35 reciprocal lattice units appears to be universally present. In addition to CDW, dynamic charge density fluctuations (CDFs) are also present with wave vectors comparable to 𝛿CDW. CDFs are present up to ≈300K and have relatively short correlation lengths of 𝜉≈20Å. Here we use Cu-𝐿3 and O-𝐾 resonant inelastic x-ray scattering (RIXS) to study the doping dependence of CDW and CDFs in La2−𝑥⁢Sr𝑥⁢CuO4. We fit our data with (quasi)elastic peaks resulting from the CDW and up to four inelastic modes associated with oxygen phonons that can be strongly coupled to the CDFs. Our analysis allows us to separate the charge correlations into three components: the CDW with wave vector 𝛿4⁢𝑎-CDW≈0.24 and two CDF components with 𝛿4⁢𝑎-CDF≈0.24 and 𝛿3⁢𝑎-CDF≈0.30. We find that for 𝑇≈𝑇𝑐 the CDW coexists with the CDFs for dopings near 𝑥=𝑝≈1/8. The 4⁢𝑎-CDW disappears beyond 𝑥=0.16 and the 4⁢𝑎-CDF beyond 𝑥=0.19, leaving only a weak 3⁢𝑎-CDF at the highest doping studied, 𝑥=0.22. Our data suggest that low-energy charge fluctuations exist up to doping 𝑥=0.19=𝑝★, where the pseudogap disappears; however, we find no evidence that they are associated with a quantum critical point.	May 2026
I16-Materials and Magnetism	Unravelling superstructure and electronic ordering in LiNiO2 bulk single crystals grown by optical floating zone technique Uthayakumar Sivaperumal , Daniel G. Porter , David J. Voneshen , Jon P. Goff Acta Crystallographica Section B Structural Science, Crystal Engineering And Materials 82 DOI: 10.1107/S2052520626001009 Diamond Proposal Number(s): [24570] Open Access Show Abstract ▼ Abstract: Although there have been several studies on the powder form, there has yet to be a report on the bulk crystal growth and its property studies of LiNiO2. In the present study, we report the first successful growth of a LiNiO2 single crystal by employing the optical floating-zone technique. Structural properties have been studied using single-crystal X-ray diffraction (XRD). The structural refinement of the single-crystal XRD data, along with the Laue diffraction patterns, confirms that this system crystallizes in a rhombohedral unit cell in space group R3m and the presence of a single grain along the length of the grown crystal. Furthermore, for the first time, we have observed and determined their superstructures as a function of temperature using single-crystal XRD. We have also conducted a study using the high flux of synchrotron X-rays to demonstrate the mechanism which drives the superstructure witnessed by the single-crystal XRD. Resonant elastic X-ray scattering was used to confirm the superstructure and the mixed valence state of different Ni sites. No additional ordering phenomena were observed, including magnetic or electronic ordering. Our study demonstrates the optimization of LiNiO2 growth parameters and provides information about atomic and electronic ordering in the system, including the onset of a superstructure phase. This will provide a basis for further work in developing improved cathode materials and understanding quantum spin liquids.	Apr 2026
I05-ARPES	Structurally driven, reversible topological phase transition in a distorted square net material Xian Yang , Chia-Hsiu Hsu , Gokul Acharya , Junyi Zhang , Md shafayat Hossain , Tyler A. Cochran , Bimal Neupane , Zi-Jia Cheng , Santosh Karki Chhetri , Byunghoon Kim , Shiyuan Gao , Yu-Xiao Jiang , Maksim Litskevich , Jian Wang , Yuanxi Wang , Jin Hu , M. Zahid Hasan Physical Review Letters 136 DOI: 10.1103/spbv-1xg6 Show Abstract ▼ Abstract: Topological materials hold immense promise for exhibiting exotic quantum phenomena, yet achieving controllable topological phase transitions remains challenging. Here, we demonstrate a structurally driven, reversible topological phase transition in the distorted square net material GdPS, induced via in situ potassium dosing. Using angle-resolved photoemission spectroscopy and first principles calculations, we demonstrate a cascade of topological phases in the subsurface P layer: from a large, topologically trivial band gap to a gapless Dirac cone state with a 2 eV dispersion, and finally to a two-dimensional topological insulator as inferred from theory. This evolution is driven by subtle structural distortions in the first P layer caused by potassium adsorption, which in turn contribute to the band gap closure and topological phase transition. Furthermore, the ability to manipulate the topology of a subsurface layer in GdPS offers a unique route for exploring and controlling topological states in bulk materials.	Mar 2026
I21-Resonant Inelastic X-ray Scattering (RIXS)	Chiral phonons in polar LiNbO3 Hiroki Ueda , Abhishek Nag , Carl P. Romao , Mirian Garcia-Fernandez , Ke-Jin Zhou , Urs Staub Nature Communications DOI: 10.1038/s41467-025-66911-5 Diamond Proposal Number(s): [36210] Open Access Show Abstract ▼ Abstract: Quasiparticles describe collective excitations in many-body systems, and their symmetry classification is of fundamental importance for physical processes such as excited states, transport phenomena, and phase transitions. Recent studies have introduced chirality as an additional degree of freedom in condensed matter physics, leading to a range of novel phenomena. Among these, chiral phonons are of special interest because they carry angular momentum and therefore intrinsically break time reversal symmetry, which non-trivially bridges the spin system with the lattice. Here, we directly prove the presence of chiral phonons in a prototypical polar LiNbO3 crystal. Our demonstration of chiral phonons in a ferroelectric enables in-situ electrical control of momentum-dependent “magnetic” polarization with the reversible phonon handedness. This ferroic control of phonon chirality has substantial potential in the emerging field of chiral phononics, particularly along the associated control of its phonon angular momentum.	Dec 2025

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