Field- and pressure-induced phases in Sr${}_4$Ru${}_3$O${}_{10}$: A spectroscopic investigation

Abstract

We have investigated the magnetic-field- and pressure-induced structural and magnetic phases of the triple-layer ruthenate - Sr${}_4$Ru${}_3$O${}_{10}$. Magnetic-field-induced changes in the phonon spectra reveal dramatic spin-reorientation transitions and strong magneto-elastic coupling in this material. Additionally, pressure-dependent Raman measurements at different temperatures reveal an anomalous negative Gruneisen-parameter associated with the B${}_{1g}$ mode ($\sim$ 380 cm${}^{-1}$) at low temperatures (T $<$ 75K), which can be explained consistently with the field dependent Raman data.

5 pages, 4 figures final version published in PRL 96, 067004 (2006)