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Most resonant inelastic x-ray scattering (RIXS) studies of dynamic charge order correlations in the cuprates have focused on the high-symmetry directions of the copper oxide plane. However, scattering along other in-plane directions should not be ignored as it may help understand, for example, the origin of charge order correlations or the isotropic scattering resulting in strange metal behavior. Our RIXS experiments reveal dynamic charge correlations over theq_x-q_yscattering plane in underdoped Bi₂Sr₂CaCu₂O_8+δ. Tracking the softening of the RIXS-measured bond-stretching phonon, we show that these dynamic correlations exist at energies below approximately 70 meV and are centered around a quasi-circular manifold in theq_x-q_yscattering plane with radius equal to the magnitude of the charge order wave vector,q_CO. This phonon-tracking procedure also allows us to rule out fluctuations of short-range directional charge order (i.e., centered around [q_x= ±q_CO,q_y= 0] and [q_x= 0,q_y= ±q_CO]) as the origin of the observed correlations.

The omnipresence of charge density waves (CDWs) across almost all cuprate families underpins a common organizing principle. However, a longstanding debate of whether its spatial symmetry is stripe or checkerboard remains unresolved. While CDWs in lanthanum‐ and yttrium‐based cuprates possess a stripe symmetry, distinguishing these two scenarios is challenging for the short‐range CDW in bismuth‐based cuprates. Here, high‐resolution resonant inelastic x‐ray scattering is employed to uncover the spatial symmetry of the CDW in Bi₂Sr_{2 −x}La_xCuO_{6 + δ}. Across a wide range of doping and temperature, anisotropic CDW peaks with elliptical shapes are found in reciprocal space. Based on Fourier transform analysis of real‐space models, the results are interpreted as evidence of unidirectional charge stripes, hosted by mutually 90°‐rotated anisotropic domains. This work paves the way for a unified symmetry and microscopic description of CDW order in cuprates.

Complex oxide films stabilized by epitaxial growth can exhibit large populations of point defects which have important effects on their properties. The site occupancy of pulsed laser‐deposited epitaxial terbium iron garnet (TbIG) films with excess terbium (Tb) is analyzed, in which the terbium:iron (Tb:Fe)ratio is 0.86 compared to the stoichiometric value of 0.6. The magnetic properties of the TbIG are sensitive to site occupancy, exhibiting a higher compensation temperature (by 90 K) and a lower Curie temperature (by 40 K) than the bulk Tb₃Fe₅O₁₂garnet. Data derived from X‐ray core‐level spectroscopy, magnetometry, and molecular field coefficient modeling are consistent with occupancy of the dodecahedral sites by Tb³⁺, the octahedral sites by Fe³⁺, Tb³⁺and vacancies, and the tetrahedral sites by Fe³⁺and vacancies. Energy dispersive X‐ray spectroscopy in a scanning transmission electron microscope provides direct evidence of Tb_Feantisites. A small fraction of Fe²⁺is present, and oxygen vacancies are inferred to be present to maintain charge neutrality. Variation of the site occupancies provides a path to considerable manipulation of the magnetic properties of epitaxial iron garnet films and other complex oxides, which readily accommodate stoichiometries not found in their bulk counterparts.