Magnetic Phase Diagrams of YVO₃ and TbVO₃ under High Pressure

Abstract

Magnetic states in RVO 3 (R = Y, Tb) were investigated using low-temperature and high-pressure neutrondiffraction techniques, and the pressure-temperature magnetic phase diagrams were clarified up to 6.2 GPa. We elucidated that, on application of pressure, the magnetic ground state changes from C-type spin ordering (C-SO) to G-type spin ordering (G-SO); this corresponds to the orbital ground-state switching from G-type orbital ordering (G-OO) to C-type orbital ordering (C-OO). It is also interesting that the G-SO transition occurs simultaneously with the C-OO transition, but not with the G-OO one. When the transition temperature of C-OO exceeds that of G-OO under high pressure, the G-OO phase vanishes completely, and a simultaneous spin and orbital order-disorder phase transition occurs. Such a transition is the first case in perovskite-type transition-metal oxides.

Fingerprints of spin-orbital polarons and of their disorder in the photoemission spectra of doped Mott insulators with orbital degeneracy

“…Furthermore, it was shown that charged defects tend to enhance orbital Peierls dimerization [67]. An important motivation for the investigation of the cubic vanadates is a large experimental data base for these systems, which includes the phase diagrams of many undoped compounds [48][49][50] and their pressure dependence [68], as well as the doping dependence of the optical conductivity for several systems [57]. In this work, our focus is on the doping dependence of the PES spectra of the vanadium perovskites [69][70][71].…”

Symmetry Origin of the Dzyaloshinskii–Moriya Interaction and Magnetization Reversal in YVO3

“…On lowering the temperature, because of a tetragonal distortion of the VO 6 octahedra, the t 2g orbitals split into a doublet of lower energy and singlet of higher energy, resulting in orbital-ordered (OO) , states with anisotropic magnetic interactions that strongly influence the magnetic ground state. It is known that the G-type orbital ordering (G-OO) favors a C-type antiferromagnetic (AFM) ordering (C-AFM), while the C-type orbital ordering (C-OO) results in G-type AFM ordering (G-AFM) due to the coupling between the spin and orbital degrees of freedom. − In all orthovanadates, except for LaVO 3 , the spin ordering takes place following the orbital ordering temperature . Various orbital ordered states, manifested by octahedral tilting, Jahn–Teller distortion, and spin orders are observed, ,,− and even complex electronic and magnetic phases have been reported for smaller R-ions, such as Y, Gd, and Er. , …”

Coupling of electronic and structural degrees of freedom in vanadate superlattices

“…This is also evident from the spin-orbital phase diagram of RVO 3 which varies widely with the V-O-V bond angle [24,27]. Experimentally, this was examined in high-pressure studies, which showed that the ground state of RVO 3 can be altered under sufficient pressure [43][44][45]. This lattice coupling was also inspected in thin films of LaVO 3 [46][47][48][49] and PrVO 3 [50,51], where biaxial epitaxial strain was utilized to modify their ordering temperatures.…”