Strongly canted antiferromagnetic ground state in Cu3 OH 2F4

An unique crystal structure of copper hydroxyl-fluorite, Cu3(OH)2F4, hosts the trimerized chains of both edge-sharing and corner-sharing CuO2F2 plaquettes. The results of the comprehensive study of this compound, including new synthetic route, measurements of specific heat, ac- and dc-susceptibility, pulsed field magnetization, electron spin resonance, muon spin rotation and relaxation and first principles calculations are presented. The data evidence magnetic phase transition at TC = 12.5 K into canted antiferromagnetic state which is due to antisymmetric Dzyaloshinskii-Moriya (DM) exchange interaction. No alteration of DM component stemming from the intrinsic features of the crystal lattice in Cu3(OH)2F4 results in unusually large spontaneous magnetization. At T < TC, the remanence MR constitutes significant portion of saturation magnetization MS which defines the canting angle φ = 4°. © 2018 Elsevier B.V

Co NO3 2 as an inverted umbrella type chiral noncoplanar ferrimagnet

The low dimensional magnetic systems tend to reveal exotic spin liquid ground states or form peculiar types of long range order. Among systems of vivid interest are those characterized by the triangular motif in two dimensions. The realization of either ordered or disordered ground state in triangular, honeycomb, or kagome lattices is dictated by the competition of exchange interactions, also being sensitive to anisotropy and the spin value of magnetic ions. While the low spin Heisenberg systems may arrive to a spin liquid long range entangled quantum state with emergent gauge structures, the high spin Ising systems may establish the rigid noncollinear structures. Here, we present the case of chiral noncoplanar inverted umbrella type ferrimagnet formed in cobalt nitrate Co NO3 2 below TC 3K with the comparable spin and orbital contributions to the total magnetic momen