Probing Spin-Lattice Correlations in Hexagonal RMnO3 Multiferroics*

The hexagonal multiferroic system RMnO3 is known to exhibit strong spin-lattice correlations based on bulk thermal expansion measurements. Enhanced correlations at the spin ordering temperatures are observed. In this work, we examine the local structure about the R and Mn sites in order to determine the changes in atomic interactions which coincide with the spin alignments. Measurements over a abroad range of temperatures are presented and estimates of the changes in atomic bond distances are given.