Pressure effects on magnetic and structural properties of pure and substitutedSrRuO3

An influence of hydrostatic pressure on phase transition temperature $T_C$, spontaneous magnetization $M_0$, coercive field $H_C$, and remanent magnetization $M_R$, has been investigated for the parent perovskite ${\mathrm{SrRuO}}_3$ and substituted ruthenates with decreased $({\mathrm{La}}_{0.2}{\mathrm{Sr}}_{0.8}{\mathrm{RuO}}_3,{\mathrm{SrRu}}_{0.9}{\mathrm{Mn}}_{0.1}{\mathrm{O}}_3)$ and increased $\left({\mathrm{SrRu}}_{0.9}{\mathrm{Cr}}_{0.1}{\mathrm{O}}_3\right)$ Curie temperature. We have observed a decrease of $T_C$ with pressure for all of the studied samples, however, the lowering of $T_C$ with pressure $(d{T}_C∕dP)$ is not correlated with the value of $T_C$ at ambient pressure. The spontaneous magnetization and coercive field remain unchanged for most of the samples, except the ${\mathrm{La}}_{0.2}{\mathrm{Sr}}_{0.8}{\mathrm{RuO}}_3$ sample, where spontaneous magnetization decreases with increasing pressure. For ${\mathrm{SrRuO}}_3$, structural study by neutron powder diffraction shows clear contraction of the $\mathrm{Ru}\text{−}\mathrm{O}$ bond lengths under external pressure whereas bond angles and the orthorhombic distortion remain constant at 295 and $50\mathrm{K}$. The weakening of the ferromagnetic interactions with increasing pressure is consistent with complex band structure effects through a combination of modulation of the hybridization caused by contraction of the $\mathrm{Ru}\text{−}\mathrm{O}$ bonds and with the significant role of the direct $\mathrm{Ru}\text{−}\mathrm{Ru}$ interactions.