Orbital-ordering driven structural distortion in metallic SrCrO3

Abstract

In contrast to the previous reports that the divalent perovskite SrCrO${}_3$ was believed to be cubic structure and nonmagnetic metal, recent measurements suggest coexistence of majority tetragonally distorted weak antiferromagnetic phase and minority nonmagnetic cubic phase. Within the local (spin) density approximation (L(S)DA) our calculations confirm that a slightly tetragonally distorted phase indeed is energetically favored. Using the correlated band theory method (LDA+ Hubbard U) as seems to be justified by the unusual behavior observed in SrCrO${}_3$, above the critical value $U_c$=4 eV only the distorted phase undergoes an orbital-ordering transition, resulting in $t_{2g}^2-->d_{xy}^1$($d_{xz}{d}_{yz}$)${}^1$ corresponding to the filling of the $d_{xy}$ orbital but leaving the other two degenerate. The Fermi surfaces of the cubic phase are simple with nesting features, although the nesting wavevectors do not correlate with known data. This is not uncommon in perovskites; the strongly directional d-d bonding often leads to boxlike Fermi surfaces, and either the nesting is not strong enough, or the matrix elements are not large enough, to promote instabilities. Fixed spin moment calculations indicate the cubic structure is just beyond a ferromagnetic Stoner instability (IN(0)~1.1) in L(S)DA, and that the energy is unusually weakly dependent on the moment out to 1.5${\mu }_B$/Cr (varying only by 11 meV/Cr), reflecting low energy long-wavelength magnetic fluctuations. We observe that this system shows strong magneto-phonon coupling (change in Cr local moment is ~7.3 ${\mu }_B$/Å) for breathing phonon modes.

7 pages and 8 embedded figures

References in corpus (7)

• Electron-Hole Symmetry and Magnetic Coupling in Antiferromagnetic LaOFeAs
• Charge Disproportionation and Spin Ordering Tendencies in Na(x)CoO2
• CaCrO3: an anomalous antiferromagnetic metallic oxide
• Orbital-selective Mott-Hubbard transition in the two-band Hubbard model
• Orbital selective insulator-metal transition in V2O3 under external pressure
• Disproportionation Transition at Critical Interaction Strength: Na${}_{1/2}$CoO${}_2$
• Fermi Velocity Spectrum and Incipient Magnetism in TiBe2

Cited by in corpus (19)

• Hubbard U and Hund's Exchange J in Transition Metal Oxides: Screening vs. Localization Trends from Constrained Random Phase Approximation
• Large spin-phonon coupling and magnetically-induced phonon anisotropy in Sr$M$O${}_3$ perovskites ($M$=V,Cr,Mn,Fe,Co)
• Evaluation of Half-metallic Antiferromagnetism in ${\mathcal{A}}_2$CrFeO${}_6$ ({$\mathcal{A}$}=La, Sr
• Compensated Half-metallicity in the Trigonally Distorted Perovskite-type NiCrO${}_3$
• Unusual magnetic structure of high-pressure synthesized perovskites ACrO3(A=Sc, In, Tl)
• Coexistence of Triple Nodal Points, Nodal Links, and Unusual Flat Bands in intermetallic $\mathcal{A}$Pd${}_3$ ($\mathcal{A}$=Pb, Sn)
• Epitaxial strain control of hole-doping induced phases in a multiferroic Mott insulator Bi2FeCrO6
• First-principles DFT+\emph{U} study of structural and electronic properties of PbCrO${}_3$
• Perovskite BaCrO_{3}: completing a materials system with an anomalous Mott transition
• Importance of tetrahedral coordination for high-valent transition metal oxides: YCrO${}_4$ as a model system
• Coupled nonpolar-polar metal-insulator transition in 1:1 SrCrO${}_3$/SrTiO${}_3$ superlattices: A first-principles study
• Orbital ordering, ferroelasticity, and the large pressure induced volume collapse in PbCrO3
• Stability of Room Temperature Compensated Half-Metallicity in Cr-based Inverse-Heusler Compounds
• Cooperative effects of Jahn-Teller distortion, magnetism and Hund's coupling in the insulating phase of BaCrO${}_3$
• Strain and Spin-Orbit Coupling Induced Orbital-Ordering in Mott Insulator BaCrO3
• First-principles study of the electronic, magnetic, and crystal structure of perovskite molybdates
• Effects of Magnetovolume and Spin-orbit Coupling in the Ferromagnetic Cubic Perovskite BaRuO3
• Strain control of the metal-insulator transition in epitaxial SrCrO${}_3$ thin films
• Effect of spin-orbit coupling on spin and orbital ordering in Sr${}_{n+1}$Cr${}_n$O${}_{3n+1}$, $n=1,2$