Figure 1: Phonons measured using a triple-axis spectrometer.
From: Phonon localization drives polar nanoregions in a relaxor ferroelectric
(a) On left, spectrum measured using the BT7 triple-axis spectrometer along Q=[2, K, 0] at 883 K, which is a temperature well above the Burns temperature (Td≈680 K). The open circles indicate the peak positions from fits to the TA and TO modes and a weaker mode inbetween. Panels on the right side show fits to the modes in the neutron spectrum at a few values of K and integrated K=[0.375, 0.5], with data offset in intensity for clarity. (b) The same spectrum and fits measured at 688 K, near Td. (c) Spectrum at 488 K, a temperature between TC and Td. A resonant crossing with the TO and the weaker mode is indicated at K=0.2. (d) Spectrum at 293 K, a temperature below TC. Uncertainties are statistical and represent one s.d.
