In this work we report on the local structure of Ti in SrTi 16O3 (STO16) and SrTi18O3 (STO18) investigated in the low temperature range (6-300 K) by extended x-ray absorption fine structure and x-ray absorption near edge structure (XANES) spectroscopy at Ti K-edge and by optical second harmonic generation (SHG). By comparing XANES of STO16 and STO18 we have identified the isotopic effect which produces at T < 100 K a noticeable difference in the measured mean square relative displacements (MSRD) of Ti-O1 bonds: while STO16 follow the expected Einstein-like behavior, for STO18 we have measured an increase of MSRD values with decreasing temperature. This is an indication of an increasing off-center position of the Ti atoms in the TiO6 octahedra. © 2014 The Royal Swedish Academy of Sciences.
Local structure studies of SrTi16O3and SrTi18O3
Rocca, Francesco;
2014-01-01
Abstract
In this work we report on the local structure of Ti in SrTi 16O3 (STO16) and SrTi18O3 (STO18) investigated in the low temperature range (6-300 K) by extended x-ray absorption fine structure and x-ray absorption near edge structure (XANES) spectroscopy at Ti K-edge and by optical second harmonic generation (SHG). By comparing XANES of STO16 and STO18 we have identified the isotopic effect which produces at T < 100 K a noticeable difference in the measured mean square relative displacements (MSRD) of Ti-O1 bonds: while STO16 follow the expected Einstein-like behavior, for STO18 we have measured an increase of MSRD values with decreasing temperature. This is an indication of an increasing off-center position of the Ti atoms in the TiO6 octahedra. © 2014 The Royal Swedish Academy of Sciences.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
