Zigzag antiferromagnetic quantum ground state in monoclinic honeycomb lattice antimonatesA3Ni2SbO6(A=<

Abstract

We present a comprehensive experimental and theoretical study of the electronic and magnetic properties of two quasi-two-dimensional (2D) honeycomb-lattice monoclinic compounds A 3 Ni 2 SbO 6 (A=Li, Na). Magnetic susceptibility and specific heat data are consistent with the onset of antiferromagnetic (AFM) long range order at low temperatures with Néel temperatures ~ 14 and 16 K for Li 3 Ni 2 SbO 6 and Na 3 Ni 2 SbO 6 , respectively. The effective magnetic moments of 4.3  B /f.u. (Li 3 Ni 2 SbO 6 ) and 4.4  B /f.u. (Na 3 Ni 2 SbO 6 ) indicate that Ni 2+ is in a high-spin configuration (S=1). The temperature dependence of the inverse magnetic susceptibility follows the Curie-Weiss law in the high-temperature region and shows positive values of the Weiss temperature ~ 8 K (Li 3 Ni 2 SbO 6 ) and ~12 K (Na 3 Ni 2 SbO 6 ) pointing to the presence of nonnegligible ferromagnetic interactions, although the system orders AFM at low temperatures. In addition, the magnetization curves reveal a field-induced (spin-flop type) transition below T N that can be related to the magnetocrystalline anisotropy in these systems. These observations are in agreement with density functional theory calculations, which show that both antiferromagnetic and ferromagnetic intralayer spin exchange couplings between Ni 2+ ions are present in the honeycomb planes supporting a zigzag antiferromagnetic ground state. Based on our experimental measurements and theoretical calculations we propose magnetic phase diagrams for the two compounds. 75.30.Kz; 75.10.Dg; 75.30.Gw; 75.30.Et

Orbitally induced hierarchy of exchange interactions in the zigzag antiferromagnetic state of honeycomb silver delafossite Ag3Co2SbO6

“…S3). It is worth to mention that the spin-reorientation-type transitions have been reported recently for several related antimonates: for example, Na 3 Co 2 SbO 6 [61], Li 3 Ni 2 SbO 6 [63], Na 3 Ni 2 SbO 6 [76], Li 4 FeSbO 6 [67]. …”

“…1 It was found that similarly to related honeycomb lattice antimonates A 3 Ni 2 SbO 6 (A = Li, Na) [76] and the lowest total energy corresponds to the AFM zigzag state. It is important to mention that this type ordering has been recently evidenced for honeycomb-lattice delafossites Cu 3 Ni 2 SbO 6 and Cu 3 Co 2 SbO 6 as refined experimentally from low temperature neutron diffraction studies [40,41].…”

Spin Correlations and Short‐Range Magnetic Order in the Honeycomb‐Layered Na2Ni2TeO6

“…The corresponding J 1 – J 2 – J 3 quantum model was described in previous studies, where J i corresponds to exchange interactions between an atom and its i th neighbor. Depending on the sign of J 1 and the sign and ratio of J 2 / J 1 and J 3 / J 1 , different nontrivial spin configurations could be realized such as “zigzag,” “stripe,” different spiral structures, etc …”

“…In the structure, one can distinguish well‐ordered magnetoactive layers with Ni and Te atoms isolated from each other by nonmagnetic Na‐contained layers (Figure ). The edge‐sharing NiO 6 octahedra form a honeycomb lattice, where the TeO 6 octahedron is located in the center of each “comb.” Due to such crystal structure, Na 2 Ni 2 TeO 6 could be attributed to a quasi‐2D system, for which the magnetic interaction between adjacent Ni 2 TeO 6 layers is much less than intralayer exchanges or nonexistent . It has to be noted that the replacement of the composition in A 2 M 2 TeO 6 has a direct influence on its magnetic properties.…”

Anisotropy-governed competition of magnetic phases in the honeycomb quantum magnet Na3Ni2SbO6 studied by dilatometry and high-frequency ESR

“…[11]. Static magnetisation was studied in magnetic fields up to 15 T by means of a home-built vibrating sample magnetometer (VSM) and in fields up to 5 T in a Quantum Design MPMS-XL5 SQUID magnetometer.…”