Observation of a pressure-induced transition from interlayer ferromagnetism to intralayer antiferromagnetism in ${\mathrm{Sr}}_4{\mathrm{Ru}}_3{\mathrm{O}}_{10}$

${\mathrm{Sr}}_4{\mathrm{Ru}}_3{\mathrm{O}}_{10}$ is a Ruddlesden-Popper compound with triple Ru-O perovskite layers separated by Sr-O rock-salt layers. This compound presents a rare coexistence of interlayer $(c$-axis) ferromagnetism and intralayer (basal-plane) metamagnetism at ambient pressure. Here we report the observation of pressure-induced, intralayer itinerant antiferromagnetism arising from the interlayer ferromagnetism. The application of modest hydrostatic pressure generates an anisotropy that may cause a flattening and a tilting of ${\mathrm{RuO}}_6$ octahedra. All magnetic and transport results from this study indicate these lattice distortions diminish the $c$-axis ferromagnetism and basal-plane metamagnetism, and induce a basal-plane antiferromagnetic state. The unusually large magnetoelastic coupling and pressure tunability of ${\mathrm{Sr}}_4{\mathrm{Ru}}_3{\mathrm{O}}_{10}$ makes it a model system for studies of itinerant magnetism.

Figure 1

(a) Temperature dependence of the magnetization $M$ at ${\mu }_{\mathrm{o}}H=0.01\mathrm{T}$, and (b) isothermal magnetization $M\left(H\right)$ at $T=1.8$ K for both the basal-plane $M_{\mathrm{ab}}$ and the $c$-axis $M_{\mathrm{c}}$ at ambient pressure. Inset: Schematic of the triple-layered crystal structure; the curved arrows indicate the rotation of the ${\mathrm{RuO}}_6$ octahedra. Note that the data in this figure, which was from our earlier work [21], were taken at ambient pressure without the pressure cell, and they are presented here only to serve as part of the introduction of the title material.

Figure 2

Temperature dependence of the magnetization $M$ at ${\mu }_{\mathrm{o}}H=0.1\mathrm{T}$ for (a) the basal plane $M_{\mathrm{ab}}$, (b) the $c$-axis $M_{\mathrm{c}}$ at representative pressures, and (c) $M_{\mathrm{ab}}$ and $M_{\mathrm{c}}$ at $P=10$ kbar for comparison. Insets in (a) and (b): $1/\mathrm{\Delta }\chi$ at $P=0$ and 10 kbar vs $T$, where $\mathrm{\Delta }\chi =$ magnetic susceptibility χ–Pauli susceptibility ${\chi }_{\mathrm{o}}$, for the basal plane and the $c$ axis, respectively. Inset in (c): $M_{\mathrm{ab}}$ and $M_{\mathrm{c}}$ at $P=0$ kbar. (d) Schematic for pressure-induced changes in the spin configuration. Note that the magnitude of $M_{\mathrm{ab}}$ (and $M_{\mathrm{c}})$ rapidly increases (decreases) with $P$, which is highlighted by the two broad vertical arrows.

Figure 3

Temperature dependence of the electrical resistivity for (a) the basal plane ${\rho }_{\mathrm{ab}}$ and (b) the $c$ axis ${\rho }_{\mathrm{c}}$ at representative pressures. Note the modest decrease in ${\rho }_{\mathrm{ab}}$ and the considerable increase in ${\rho }_{\mathrm{c}}$ with $P$, which is marked by the broad arrow. (c) The exponent α of ${\rho }_{\mathrm{c}}\sim T^{\alpha }$ as a function of pressure $P$. Note that the shaded area marks the rapid change in α. (d) Schematic for pressure-induced changes in the ${\mathrm{RuO}}_6$ octahedra.

Figure 4

The isothermal magnetization at $T=2$ K for (a) the basal plane $M_{\mathrm{ab}}$ for $H\left|\right|$ basal plane and (b) the $c$ axis $M_{\mathrm{c}}$ for $H\left|\right|c$ axis at a few representative pressures.

Figure 5

Magnetic-field dependence of the electrical resistivity at 2 K for (a) the basal plane ${\rho }_{\mathrm{ab}}$, (b) the $c$ axis ${\rho }_{\mathrm{c}}$ at representative pressures, and (c) ${\rho }_{\mathrm{ab}}$ and ${\rho }_{\mathrm{c}}$ and $M_{\mathrm{ab}}$ (right scale) at $P=8$ kbar for comparison. (d) Schematic for field-induced changes in the spin configuration. Note that the two broad horizontal arrows in Fig. 5 are to highlight the rapid decrease in $H_{\mathrm{c}}$ with $P$, and the vertical dashed line in Fig. 5 indicates $H_c$.

Figure 6

A $T\text{−}P$ phase diagram generated based on the magnetic and transport results. Note that $T_{\mathrm{C}}$ and $T_{\mathrm{M}}$ appear to merge as the antiferromagnetic state is fully developed at $P\ge 25$ kbar. Note that the shaded areas near 10 kbar mark a crossover from the $c$-axis FM state to a predominately basal-plane AFM state.