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Abstract Evidence of chirality was observed at the Fe metal center in Fe(III) spin crossover coordination salts [Fe(qsal)₂][Ni(dmit)₂] and [Fe(qsal)₂](TCNQ)₂from x-ray absorption (XAS) spectroscopy at the Fe 2p_3/2core threshold. Based on the circularly polarized XAS data, the x-ray natural circular dichroism for [Fe(qsal)₂][Ni(dmit)₂] and [Fe(qsal)₂](TCNQ)₂is far stronger than seen for [Fe(qsal)₂]Cl suggesting this natural circular dichroism signature is a ligand effect rather than a result of just a loss of octahedral symmetry on the Fe core. The larger the chiral effects in the Fe 2p core to bound XAS, the greater the perturbation of the Fe 2p_3/2to 2p_1/2spin–orbit splitting seen in the XAS spectra. 

Abstract Understanding intrinsic exchange bias in nominally single‐component ferromagnetic or ferrimagnetic materials is crucial for simplifying related device architectures. However, the mechanisms behind this phenomenon and its tunability remain elusive, which hinders the efforts to achieve unidirectional magnetization for widespread applications. Inspired by the high tunability of ferrimagnetic inverse spinel NiCo₂O₄, the origin of intrinsic exchange bias in NiCo₂O₄(111) films deposited on Al₂O₃(0001) substrates are investigated. The comprehensive characterizations, including electron diffraction, X‐ray reflectometry and spectroscopy, and polarized neutron reflectometry, reveal that intrinsic exchange bias in NiCo₂O₄(111)/Al₂O₃(0001) arises from a reconstructed antiferromagnetic rock‐salt Ni_xCo_1‐xO layer at the interface between the film and the substrate due to a significant structural mismatch. Remarkably, by engineering the interfacial structure under optimal growth conditions, it can achieve exchange bias larger than coercivity, leading to unidirectional magnetization. Such giant intrinsic exchange bias can be utilized for realistic device applications. This work establishes a new material platform based on NiCo₂O₄, an emergent spintronics material, to study tunable interfacial magnetic and spintronic properties. 

Abstract Boron (B) alloying transforms the magnetoelectric antiferromagnet Cr₂O₃into a multifunctional single‐phase material which enables electric field driven π/2 rotation of the Néel vector. Nonvolatile, voltage‐controlled Néel vector rotation is a much‐desired material property in the context of antiferromagnetic spintronics enabling ultralow power, ultrafast, nonvolatile memory, and logic device applications. Néel vector rotation is detected with the help of heavy metal (Pt) Hall‐bars in proximity of pulsed laser deposited B:Cr₂O₃films. To facilitate operation of B:Cr₂O₃‐based devices in CMOS (complementary metal‐oxide semiconductor) environments, the Néel temperature,T_N, of the functional film must be tunable to values significantly above room temperature. Cold neutron depth profiling and X‐ray photoemission spectroscopy depth profiling reveal thermally activated B‐accumulation at the B:Cr₂O₃/ vacuum interface in thin films deposited on Al₂O₃substrates. The B‐enrichment is attributed to surface segregation. Magnetotransport data confirm B‐accumulation at the interface within a layer of ≈50 nm thick where the device properties reside. HereT_Nenhances from 334 K prior to annealing, to 477 K after annealing for several hours. Scaling analysis determinesT_Nas a function of the annealing temperature. Stability of post‐annealing device properties is evident from reproducible Néel vector rotation at 370 K performed over the course of weeks. 

The interband transitions of UO₂are validated independently through cathode luminescence. A picture emerges consistent with density functional theory. While theory is generally consistent with experiment, it is evident from the comparison of UO₂and ThO₂that the choice of functional can significantly alter the bandgap and some details of the band structure, in particular at the conduction band minimum. Strictly ab initio predictions of the optical properties of the actinide compounds, based on density functional theory alone, continue to be somewhat elusive. 

Abstract Theoretical and experimental investigations of various exfoliated samples taken from layered In₄Se₃crystals are performed. In spite of the ionic character of interlayer interactions in In₄Se₃and hence much higher calculated cleavage energies compared to graphite, it is possible to produce few‐nanometer‐thick flakes of In₄Se₃by mechanical exfoliation of its bulk crystals. The In₄Se₃flakes exfoliated on Si/SiO₂have anisotropic electronic properties and exhibit field‐effect electron mobilities of about 50 cm² V⁻¹ s⁻¹at room temperature, which are comparable with other popular transition metal chalcogenide (TMC) electronic materials, such as MoS₂and TiS₃. In₄Se₃devices exhibit a visible range photoresponse on a timescale of less than 30 ms. The photoresponse depends on the polarization of the excitation light consistent with symmetry‐dependent band structure calculations for the most expectedaccleavage plane. These results demonstrate that mechanical exfoliation of layered ionic In₄Se₃crystals is possible, while the fast anisotropic photoresponse makes In₄Se₃a competitive electronic material, in the TMC family, for emerging optoelectronic device applications.