Dimer Crystallization Induced by Elemental Substitution in the Honeycomb Lattice of Ru1-xOsxCl3

Abstract

Substitution effects of Os for Ru in α-RuCl3 are investigated in a wide composition range of 0 =< x =< 0.67 in Ru1-xOsxCl3 by X-ray and electron diffraction, magnetic susceptibility, heat capacity, and Raman spectroscopy measurements. Apart from the Kitaev physics with antiferromagnetic interactions increasing with x, a rich phase diagram is obtained, which includes an antiferromagnetic long-range order below 12 K for x =< 0.15, a dome-shaped spin-singlet dimer phase below 130 K for 0.15 =< x =< 0.40, and a magnetic short-range order for x > 0.40. A dimerization as similarly observed in α-RuCl3 under high pressure occurs in the spin-singlet phase. It is suggested that Ru-Os pairs in the solid solutions tend to form dimers with short bonds and trigger the first-order transition in the presence of pseudo-threefold rotational symmetry for dimerization around a substituted Os atom only at low substitutions. This is a rare example of molecular orbital crystallization induced by elemental substitution in a highly disordered system. The short-range order at high substitutions may be related to a random-singlet state stabilized by bond disorder in the honeycomb net.

arXiv comment13 pages, 14 figures

References in corpus (33)

• Anyons in an exactly solved model and beyond
• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Fermi-liquid instabilities at magnetic quantum phase transitions
• Majorana quantization and half-integer thermal quantum Hall effect in a Kitaev spin liquid
• $\alpha$-RuCl3: a Spin-Orbit Assisted Mott Insulator on a Honeycomb Lattice
• The monoclinic crystal structure of $\alpha$-RuCl${}_3$ and the zigzag antiferromagnetic ground state
• Low-temperature crystal and magnetic structure of $\alpha$-RuCl3
• Successive magnetic phase transitions in $\mathbf{\alpha }$-RuCl${}_3$: XY-like frustrated magnet on the honeycomb lattice
• Hunting Majorana Fermions in Kitaev Magnets
• Anisotropic Ru3+ 4d5 magnetism in the alpha-RuCl3 honeycomb system: susceptibility, specific heat and Zero field NMR
• Phase Diagram of a Frustrated Quantum Antiferromagnet on the Honeycomb Lattice: Magnetic Order versus Valence-Bond Crystal formation
• Spin-orbit-entangled electronic phases in 4$d$ and 5$d$ transition-metal compounds
• Relation between Kitaev magnetism and structure in $\alpha$-RuCl${}_3$
• Phase diagram of depleted Heisenberg model for CaV4O9
• Structural instability of the rutile compounds and its relevance to the metal-insulator transition of VO2
• Pressure-induced dimerization and valence bond crystal formation in the Kitaev-Heisenberg magnet alpha-RuCl3
• Anisotropic susceptibilities in the honeycomb Kitaev system $\alpha$-RuCl${}_3$
• Proximate ferromagnetic state in the Kitaev model material $\alpha$-RuCl${}_3$
• Quantum spin-liquid behavior in the spin-1/2 random-bond Heisenberg antiferromagnet on the kagome lattice
• Competition between spin-orbit coupling, magnetism, and dimerization in the honeycomb iridates: $\alpha$-Li${}_2$IrO${}_3$ under pressure
• Nature of the randomness-induced quantum spin liquids in two dimensions
• Random-Singlet Phase in Disordered Two-Dimensional Quantum Magnets
• Pressure-induced melting of magnetic order and emergence of new quantum state in alpha-RuCl3
• Classical dimers and dimerized superstructure in orbitally degenerate honeycomb antiferromagnet
• Randomness-induced quantum spin liquid behavior in the s=1/2 random J1-J2 Heisenberg antiferromagnet on the honeycomb lattice
• Raman evidence for dimerization and Mott collapse in $\alpha$-RuCl${}_3$ under pressures
• Comparison of S=0 and S=1/2 Impurities in Haldane Chain Compound, $Y_{2}BaNi{O}_5$
• Structural Transition of Li2RuO3 Induced by Molecular-Orbit Formation
• Disorder driven spin-orbital liquid behaviour in the Ba${}_3$XSb${}_2$O${}_9$ materials
• Spin-glass state and reversed magnetic anisotropy induced by Cr doping in the Kitaev magnet $\alpha$-RuCl${}_3$
• Kitaev Spin Liquid Candidate OsxCl3 Comprised of Honeycomb Nano-Domains
• Detuning the Honeycomb of the α-RuCl3 Kitaev lattice: A case of Cr3+ dopant
• Spin dynamics of the antiferromagnetic Heisenberg model on a kagome bilayer

Cited by in corpus (2)

• Dilution of the magnetic lattice in the Kitaev candidate $\alpha$-RuCl${}_3$ by Rh${}^{3+}$ doping
• A primer on Kitaev Model: Basic aspects, material realization, and recent experiments