Spin state of Co${}^{3+}$ in LaCo${}_{1-x}$Rh${}_x$O${}_3$ investigated by structural phenomena

Abstract

Neutron diffraction for a polycrystalline sample of LaCo${}_{0.8}$Rh${}_{0.2}$O${}_3$ and synchrotron x-ray diffraction for polycrystalline samples of LaCo${}_{0.9}$Rh${}_{0.1}$O${}_3$ and LaCo${}_{0.8}$Rh${}_{0.2}$O${}_3$ have been carried out in order to investigate the structural properties related with the spin state of Co${}^{3+}$ ions. We have found that the values of the Co(Rh)-O bond lengths in the Co(Rh)O${}_6$ octahedron of LaCo${}_{0.8}$Rh${}_{0.2}$O${}_3$ are nearly identical at 10 K. The lattice volume for the Rh${}^{3+}$ substituted samples decreases with the thermal expansion coefficient similar to that of LaCoO${}_3$ from room temperature, and ceases to decrease around 70 K. These experimental results favor a mixed state consisting of the high-spin-state and low-spin-state Co${}^{3+}$ ions, and suggest that the high-spin-state Co${}^{3+}$ ions are thermally excited in addition to those pinned by the substituted Rh${}^{3+}$ ions.

6 pages, 5 figures

References in corpus (4)

• The spin state transition in LaCoO${}_3$; revising a revision
• Stabilization of the high-spin state of Co${}^{3+}$ in LaCo${}_{1-x}$Rh${}_x$O${}_3$
• Weak Ferromagnetism in LaCo1-xRhxO3: Anomalous Magnetism Emerging between Two Nonmagnetic End Phases
• Ga${}^{3+}$-substitution effects in the weak ferromagnetic oxide LaCo${}_{0.8}$Rh${}_{0.2}$O${}_3$

Cited by in corpus (1)

• Anomalous magnetic and spin glass behavior in Nb substituted LaCo${}_{1-x}$Nb${}_x$O${}_3$