Double magnetic transitions and exotic field induced phase in the triangular lattice antiferromagnets Sr${}_3$Co(Nb,Ta)${}_2$O${}_9$

Abstract

Two triangular lattice antiferromagnets Sr${}_3$Co(Nb,Ta)${}_2$O${}_9$ with an effective $j_{\mathrm{eff}}=1/2$ of Co${}^{2+}$ are synthesized and their magnetic properties are investigated via magnetization and heat capacity measurements. The leading in-plane antiferromagnetic exchange coupling is estimated to be $J/k_{\mathrm{B}}\simeq 4.7$ K and 5.8 K, respectively. Both the compounds feature two-step magnetic transitions at low temperatures [($T_{N1}\simeq 1.47$ K and $T_{N2}\simeq 1.22$ K) and ($T_{N1}\simeq 0.88$ K and $T_{N2}\simeq 0.67$ K), respectively], driven by weak easy-axis anisotropy. Under magnetic field Sr${}_3$CoNb${}_2$O${}_9$ evinces a plateau at $1/3$ magnetization. Interestingly, the high field magnetization of Sr${}_3$CoTa${}_2$O${}_9$ reveals an exotic regime (between $H_{S1}$ and $H_{S2}$), below the fully polarized state in which the heat capacity at low temperatures is governed by a power law ($C_{\mathrm{p}}\propto T^{\alpha }$) with a reduced exponent $\alpha \simeq 2$. These results demonstrate an unusual field induced state with gapless excitations in the strongly frustrated magnet Sr${}_3$CoTa${}_2$O${}_9$. The complete $T-H$ phase diagram is discussed for both the compounds.

arXiv comment12 pages, 7 figures, 2 tables

References in corpus (49)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
• Quantum Spin Liquids
• Spin Dynamics of the Spin-1/2 Kagome Lattice Antiferromagnet ZnCu_3(OH)_6Cl_2
• Kitaev quantum spin liquid - concept and materialization
• Projected wavefunction study of Spin-1/2 Heisenberg model on the Kagome lattice
• Spin-Liquid State in the S = 1/2 Hyperkagome Antiferromagnet Na4Ir3O8
• Long range Neel order in the triangular Heisenberg model
• Rare-earth triangular lattice spin liquid: a single-crystal study of YbMgGaO${}_4$
• Evidence for a Field-induced Quantum Spin Liquid in $\alpha$-RuCl${}_3$
• Neel order in square and triangular lattice Heisenberg models
• Properties of an algebraic spin liquid on the kagome lattice
• Experimental Realization of Spin-1/2 Triangular-Lattice Heisenberg Antiferromagnet
• Pseudospin exchange interactions in d^7 cobalt compounds: Possible realization of the Kitaev model
• Magnetization Process and Collective Excitations in the S=1/2 Triangular-Lattice Heisenberg Antiferromagnet Ba3CoSb2O9
• Kitaev-Heisenberg Hamiltonian for High-Spin $d^7$ Mott Insulators
• Competing Spin Liquid States in the Spin-$1/2$ Heisenberg Model On Triangular Lattice
• Kitaev Spin Liquid in 3d Transition Metal Compounds
• Gapless spin-liquid state in the structurally disorder-free triangular antiferromagnet NaYbO${}_2$
• Field-induced quantum spin disordered state in spin-1/2 honeycomb magnet Na2Co2TeO6
• High pressure sequence of Ba_3NiSb_2O_9 structural phases: new $S=1$ quantum spin-liquids based on Ni^{2+}
• Sign reversal of field-angle resolved heat capacity oscillations in a heavy fermion superconductor CeCoIn${}_5$ and $d_{x^2-y^2}$ pairing symmetry
• Gapless spin liquid ground state in the S=1/2 vanadium oxyfluoride kagome antiferromagnet [NH4]2[C7H14N][V7O6F18]
• Weak-field induced nonmagnetic state in a Co-based honeycomb
• Anisotropic-Exchange Magnets on a Triangular Lattice: Spin Waves, Accidental Degeneracies, and Dual Spin Liquids
• Spin-liquid-like state in a spin-1/2 square-lattice antiferromagnet perovskite induced by $d^{10}$-$d^0$ cation mixing
• The nature of spin excitations in the one-third magnetization plateau phase of Ba${}_3$CoSb${}_2$O${}_9$
• Possible itinerant excitations and quantum spin state transitions in the effective spin-1/2 triangular-lattice antiferromagnet Na${}_2$BaCo(PO${}_4$)${}_2$
• Phase diagram of the classical Heisenberg antiferromagnet on a triangular lattice in applied magnetic field
• Strong quantum fluctuations in a quantum spin liquid candidate with a Co-based triangular lattice
• Exploring the spin-1/2 frustrated square lattice model with high-field magnetization measurements
• Magnetic phase diagrams of classical triangular and kagome antiferromagnets
• Magnetic Phase Diagram of the S=1/2 Triangular-Lattice Heisenberg Antiferromagnet Ba3CoNb2O9
• Ba8CoNb6O24: a spin-1/2 triangular-lattice Heisenberg antiferromagnet in the 2D limit
• Quantum and Thermal Phase Transitions of the Triangular SU(3) Heisenberg Model under Magnetic Fields
• Magnetic transitions in the spin S=5/2 frustrated magnet BiMn2PO6 and strong lattice softening in BiMn2PO6 and BiZn2PO6 below 200 K
• Commensurate and incommensurate magnetic order in spin-1 chains stacked on the triangular lattice in Li${}_2$NiW${}_2$O${}_8$
• Quantum magnetic properties of the spin-1/2 triangular-lattice antiferromagnet Ba${}_2$La${}_2$CoTe${}_2$O${}_{12}$
• Double phase transition in the triangular antiferromagnet Ba${}_3$CoTa${}_2$O${}_9$
• Gapless quantum spin liquid in the triangular system Sr${}_3$CuSb${}_2$O${}_9$
• Interplay of anisotropy and frustration: triple transitions in a triangular-lattice antiferromagnet
• Frustration enhanced by Kitaev exchange in a ${\tilde{\mathbf{j}}}_{\text{eff}}=\frac{1}{2}$ triangular antiferromagnet
• Magnetic Properties of New Triangular Lattice Magnets A${}_4$B'B${}_2$O${}_{12}$
• Quasi-one-dimensional magnetism in the spin-$\frac{1}{2}$ antiferromagnet BaNa${}_2$Cu(VO${}_4$)${}_2$
• Magnetic properties and signatures of moment ordering in triangular lattice antiferromagnet KCeO${}_2$
• Collinear order in a frustrated three-dimensional spin-$\frac{1}{2}$ antiferromagnet Li${}_2$CuW${}_2$O${}_8$
• Perfect kagome-lattice antiferromagnets with J${}_{eff}$ = 1/2: The Co${}^{2+}$-analogs of copper minerals volborthite and vesignieite
• Classical spin liquids in stacked triangular lattice Ising antiferromagnets
• Contrasting Magnetic Structures in SrLaCuSbO${}_6$ and SrLaCuNbO${}_6$: Spin-1/2 Quasi-Square-Lattice $J_1-J_2$ Heisenberg Antiferromagnets
• Magnetic phase diagram in three-dimensional triangular-lattice antiferromagnet Sr${}_3$CoTa${}_2$O${}_9$ with small easy-axis anisotropy

Cited by in corpus (1)

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