Lattice distortion in the spin-orbital entangled state in RVO3 perovskites

Abstract

We report a thorough study of Y${}_{0.7}$La${}_{0.3}$VO${}_3$ single crystals by measuring magnetic properties, specific heat, thermal conductivity, x-ray and neutron diffraction with the motivation of revealing the lattice response to the spin-orbital entanglement in \textit{R}VO${}_3$. Upon cooling from room temperature, the orbitally disordered paramagnetic state changes around T*$\sim$220\,K to spin-orbital entangled state which is then followed by a transition at T${}_N$=116\,K to C-type orbital ordered (OO) and G-type antiferromagnetic ordered (AF) ground state. In the temperature interval T${}_N<T<T^{\ast }$, the VO${}_{6/2}$ octahedra have two comparable in-plane V-O bonds which are longer than the out-of-plane V-O1 bond. This local structural distortion supports the spin-orbital entanglement of partially filled and degenerate yz/zx orbitals. However, this distortion is incompatible with the steric octahedral site distortion intrinsic to orthorhombic perovskites. Their competition induces a second order transition from the spin-orbital entangled state to C-OO/G-AF ground state where the long range OO suppresses the spin-orbital entanglement. Our analysis suggests that the spin-orbital entangled state and G-OO are comparable in energy and compete with each other. Rare earth site disorder favors the spin-orbital entanglement rather than a cooperative Jahn-Teller distortion. The results also indicate for LaVO${}_3$ a C-OO/G-AF state in T${}_t$\,$\le$\,T\,$\le$T${}_N$ and an orbital flipping transition at T${}_t$.

arXiv comment9 pages, 9 figures

References in corpus (19)

• Correlated quantum phenomena in the strong spin-orbit regime
• Interplay between orbital ordering and lattice distortions in LaMnO3, YVO3, and YTiO3
• Spin Order due to Orbital Fluctuations: Cubic Vanadates
• Orbital fluctuations in the different phases of LaVO3 and YVO3
• Spin-Orbital Entanglement and Violation of the Goodenough-Kanamori Rules
• Neutron diffraction study of YVO3, NdVO3, and TbVO3
• Fingerprints of spin-orbital entanglement in transition metal oxides
• Lattice Distortion and Magnetism of 3d-$t_{2g}$ Perovskite Oxides
• Quantum Versus Jahn-Teller Orbital Physics in YVO${}_3$ and LaVO${}_3$
• The crucial importance of the $t_{2g}$--$e_g$ hybridization in transition metal oxides
• One-Dimensional Confinement and Enhanced Jahn-Teller Instability in LaVO${}_3$
• Anisotropic Optic Conductivities due to Spin and Orbital Orderings in LaVO3 and YVO3: First-Principles Studies
• One-dimensional orbital fluctuations and the exotic magnetic properties of YVO${}_3$
• Probing orbital fluctuations in RVO3 (R = Y, Gd, or Ce) by ellipsometry
• Spin, orbital ordering and magnetic dynamics of LaVO3: magnetization, heat capacity and neutron scattering studies
• Effect of cation size variance on spin and orbital order in Eu${}_{1-x}$(La${}_{0.254}$Y${}_{0.746}$)${}_x$VO${}_3$
• Jahn-Teller versus quantum effects in the spin-orbital material LuVO3
• Signatures of spin-orbital states of ${t_{2g}}^2$ system in the optical conductivity : The case of $R$VO${}_3$ ($R$=Y and La)
• Dy-V magnetic interaction and local structure bias on the complex spin and orbital ordering in Dy${}_{1-x}$Tb${}_x$VO${}_3$ (x\,=\,0 and 0.2)

Cited by in corpus (5)

• Bond Ordering and Molecular Spin-Orbital Fluctuations in the Cluster Mott Insulator GaTa${}_4$Se${}_8$
• Coupling of electronic and structural degrees of freedom in vanadate superlattices
• Orbital Rotations induced by Charges of Polarons and Defects in Doped Vanadates
• Evolution of Spin-Orbital Entanglement with Increasing Ising Spin-Orbit Coupling
• Spin-phonon interactions revisited: Far-infrared emission, Raman scattering, and high-resolution x-ray diffraction at the Néel temperature in LaFeO3