X-ray Intensity Fluctuation Spectroscopy Using Nanofocused Hard X-rays: Its Application to Study of Relaxor Ferroelectrics

The use of a combination of coherent X-rays from a third-generation synchrotron light source and ultraprecise Kirkpatrick-Baez mirrors enables us to apply nanofocused hard X-rays in solid-state physics. We developed an apparatus for X-ray intensity fluctuation spectroscopy using the nanofocused hard X-rays and applied it to the study of relaxor ferroelectrics. We have successfully detected a large and slow intensity fluctuation of scattered X-rays above cubic-to-tetragonal phase transition temperature with a characteristic time scale on the order of 10 s. We speculated that the intensity fluctuation originates from domain number fluctuation, which is directly related to the dielectric response, particularly the frequency dispersion. (C) 2010 The Japan Society of Applied Physics