3D local structure analysis of relaxor ferroelectrics Pb(MgNb)O by X-ray fluorescence holography

Hu, W.; Hayashi, Koichi*; Happo, Naohisa*; Owada, Kenji; Chen, J.*; Ye, Z.-G*; Hosokawa, Shinya*; Takahashi, Masamitsu

Relaxor ferroelectrics as a class of disordered crystals possessing peculiar structure and properties have attracted significant research attention. However, quantitative analysis of its local structure and lattice distortion is difficult, and there is no report to our knowledge of direct observation of its three-dimensional local structure. In the present work, we carried our X-ray fluorescence holography experiments on Pb(MgNb)O (PMN) single crystal at BL22XU of SPring-8 and successfully obtained 3D atomic images around Nb and Pb elements up to 2 nm with atomic resolution. Our result shows the direct evidence of the rhombohedral distortion in PMN. Comparing with theoretical calculation, coexistence of two rhombohedral distortions was confirmed. In this presentation, we will discuss the short-range distortion of Pb atoms by comparing the obtained 3D atomic images around Nb at room temperature and 100 K.