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.
Categories: cond-mat.str-el