K. Kiyoto

Resonant X-ray Scattering Study at Y K-edge in Y1-xCaxTiO3

Resonant X-ray scattering (RXS) in Y 1- x Ca x TiO 3 has been investigated near the Y K -edge. The resonant signal has been clearly found at a forbidden reflection, (500), and the intensity shows an azimuthal angle dependence with a twofold symmetry. The RXS intensities have almost no Ca concentration dependence, although the RXS intensities at the Ti K -edge markedly decrease with increasing Ca concentration. The origin of the RXS at the Y K -edge is clarified to be the deviation from 180° of the Ti–O–Ti bond angle, namely, the tilts of the octahedra around the Y ion. We also discuss the RXS mechanism at the main edge of the Ti K -edge.

Charge Ordered State in Yb4As3 Studied by a Resonant X‐ray Scattering Technique

The charge ordered state in Yb4As3 has been studied by a resonant x‐ray scattering (RXS) technique near the Yb L3‐edge. The anomalous scattering factors, f′ and f″, of Yb3+ and Yb2+ have been determined using the absorption spectrum of the Yb4As3. Based on the anomalous scattering factors, the valences of the two inequivalent Yb sites, +2 25 −δ and +2 25 + 3δ, have been evaluated by the RXS intensity corresponding to the charge ordering. The fully charge ordered state of δ = 0 25 ± 0 02 was elucidated.