Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/241517
Type: Artigo
Title: Hyperhoneycomb iridate beta-Li2IrO3 as a platform for Kitaev magnetism
Author: Takayama, T.
Kato, A.
Dinnebier, R.
Nuss, J.
Kono, H.
Veiga, L. S. I.
Fabbris, G.
Haskel, D.
Takagi, H.
Abstract: A complex iridium oxide beta-Li2IrO3 crystallizes in a hyperhoneycomb structure, a three-dimensional analogue of honeycomb lattice, and is found to be a spin-orbital Mott insulator with J(eff) = 1/2 moment. Ir ions are connected to the three neighboring Ir ions via Ir-O-2-Ir bonding planes, which very likely gives rise to bond-dependent ferromagnetic interactions between the J(eff) = 1/2 moments, an essential ingredient of Kitaev model with a spin liquid ground state. Dominant ferromagnetic interaction between J(eff) = 1/2 moments is indeed confirmed by the temperature dependence of magnetic susceptibility chi(T) which shows a positive Curie-Weiss temperature theta(CW) similar to +40 K. A magnetic ordering with a very small entropy change, likely associated with a noncollinear arrangement of J(eff) = 1/2 moments, is observed at T-c = 38 K. With the application of magnetic field to the ordered state, a large moment of more than 0.35 mu(B)/Ir is induced above 3 T, a substantially polarized J(eff) = 1/2 state. We argue that the close proximity to ferromagnetism and the presence of large fluctuations evidence that the ground state of hyperhoneycomb beta-Li2IrO3 is located in close proximity of a Kitaev spin liquid.
A complex iridium oxide beta-Li2IrO3 crystallizes in a hyperhoneycomb structure, a three-dimensional analogue of honeycomb lattice, and is found to be a spin-orbital Mott insulator with J(eff) = 1/2 moment. Ir ions are connected to the three neighboring Ir ions via Ir-O-2-Ir bonding planes, which very likely gives rise to bond-dependent ferromagnetic interactions between the J(eff) = 1/2 moments, an essential ingredient of Kitaev model with a spin liquid ground state. Dominant ferromagnetic interaction between J(eff) = 1/2 moments is indeed confirmed by the temperature dependence of magnetic susceptibility chi(T) which shows a positive Curie-Weiss temperature theta(CW) similar to +40 K. A magnetic ordering with a very small entropy change, likely associated with a noncollinear arrangement of J(eff) = 1/2 moments, is observed at T-c = 38 K. With the application of magnetic field to the ordered state, a large moment of more than 0.35 mu(B)/Ir is induced above 3 T, a substantially polarized J(eff) = 1/2 state. We argue that the close proximity to ferromagnetism and the presence of large fluctuations evidence that the ground state of hyperhoneycomb beta-Li2IrO3 is located in close proximity of a Kitaev spin liquid.
Subject: Acoplamento spin-órbita
Magnetismo
Cristais
Country: Estados Unidos
Editor: American Physical Society
Citation: Hyperhoneycomb Iridate Beta-li2iro3 As A Platform For Kitaev Magnetism. Amer Physical Soc, v. 114, p. FEB-2015.
Rights: aberto
Identifier DOI: 10.1103/PhysRevLett.114.077202
Address: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.114.077202
Date Issue: 2015
Appears in Collections:IFGW - Artigos e Outros Documentos

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