Magnetism in S=1/2 Double-Perovskites with Strong Spin-Orbit Interactions

Abstract

We study magnetism on the fcc lattice with tetragonal distortions, with general exotic directional magnetic interactions allowed by symmetry. We consider two models, corresponding to a uniform tetragonal distortion, or a two-sublattice model with a tetragonal screw axis. We establish their low temperature phase diagrams in the semi-classical limit using classical optimization and consideration of fluctuations both analytically and by Monte Carlo simulation. Both order by disorder and exchange anisotropy mechanisms favor a $⟨110⟩$ easy axis for magnetization. We also show that spin-lattice coupling can give rise to an intermediate temperature paramagnetc nematic/orthorhombic phase, and discuss the transitions to/from this state. These results are relevant to a family of insulating magnetic double perovskites, and find immediate application to the ferromagnet Ba${}_2$NaOsO${}_6$.

18 pages, 12 figures

References in corpus (3)

• Long range magnetic ordering in Na${}_2$IrO${}_3$
• Ferromagnetism in the Mott insulator Ba2NaOsO6
• Non-coplanar and counter-rotating incommensurate magnetic order stabilized by Kitaev interactions in $\gamma$-Li2IrO3

Cited by in corpus (12)

• Anisotropic field-induced ordering in the triangular-lattice quantum spin liquid NaYbSe${}_2$
• Field-induced instability of the quantum-spin-liquid ground state in the $J_{\mathrm{eff}}=\frac{1}{2}$ triangular-lattice compound NaYbO${}_2$
• Novel Magnetism and Local Symmetry Breaking in a Mott Insulator with Strong Spin Orbit Interactions
• Detection of multipolar orders in the spin-orbit-entangled 5d Mott insulator Ba2MgReO6
• Successive Symmetry Breaking in a Jeff = 3/2 Quartet in the Spin-Orbit Coupled Insulator Ba2MgReO6
• Interplay between multipolar spin interactions, Jahn-Teller effect and electronic correlation in a $J_{eff}=\frac{3}{2}$ insulator
• Phase transition preceding magnetic long-range order in the double perovskite Ba2NaOsO6
• Antiferromagnetic long-range order in $5d^1$ double-perovskite Sr${}_2$MgReO${}_6$
• Calculated g-factors of 5d double perovskites Ba2NaOsO6 and Ba2YOsO6
• Possible quadrupole order in tetragonal Ba2CdReO6 and chemical trend in the ground states of 5d1 double perovskites
• Dynamic Jahn-Teller Phenomena in Heavy Transition Metal Compounds
• Enhanced magnetism and suppressed magnetoelastic coupling induced by electron doping in Ca${}_{1-x}$Y${}_x$MnReO${}_6$