Polarized High-Energy-Resolution Fluorescence Detection-X-ray Absorption Near-Edge Structure of the (La,Sr)(Al,Ta)O₃ Single Crystal at the La L₁‑Edge

High-energy resolution La L₁-edge X-ray absorption near-edge structure (XANES) spectra of LaAlO₃ and a La-containing cubic perovskite oxide were obtained by using the high-energy-resolution fluorescence detection (HERFD) method. In the pre-edge region, two new peaks, which were not observed with the conventional measurement method, were found in the high-resolution XANES spectra and identified as d_z² and d_x²–y² final states and d_xy, d_yz, and d_zx final states, respectively, from XANES simulations and theoretical investigations.