CoV₂O₆ Single Crystals Grown in a Closed Crucible: Unusual Magnetic Behaviors with Large Anisotropy and ¹/₃ Magnetization Plateau

Abstract

Single crystals of CoV(2)O(6) were obtained in a closed crucible using a flux method. Magnetic measurements showed that this material displays a large magnetic anisotropy and a 1/3 magnetization plateau under a magnetic field applied along the c axis.

Sinusoidal magnetic structure in a three-dimensional antiferromagneticCo2(OH)AsO4: Incommensurate-commensurate magnetic phase transition

“…If we consider the commensurate AF structure of the isomorphous Co 2 ͑OH͒PO 4 phase, 11 the appearance of an amplitude modulated by changing the PO 4 3− for AsO 4 3− anions demonstrated the strong anisotropy magnetocristalline present in these Co 2 ͑OH͒XO 4 ͑X = P and As͒ phases. The main magnetic exchange pathways present in these isomorphous compounds are shown in Table IV It is worth mentioning the comparison of the magnetic exchange interaction, Co͑1͒-O͑3͒-Co͑2͒, between dimers and their neighbor chains in the Co 2 ͑OH͒XO 4 ͑X = P and As͒ phases ͑Table IV and Fig.…”

“…In this way, in the phosphate phase, this magnetic exchange has a striking angle of 107°͑ for ferromagnetic interactions through the xz plane͒ which was considered essential in the competition between dimers and chains in order to ensure cooperativeness of the freezing process associated to a spin-glass state of this phase. 11 However, the substitution of the PO 4 3− by AsO 4 3− anions modifies substantially the magnetic exchange Co͑1͒-O͑3͒-Co͑2͒ angle from 107°to 116.9°for the phosphate and arsenate, respectively, relaxing the magnetic frustration system of Co 2 ͑OH͒PO 4 leading to an incommensurate phase with antiferromagnetic interactions ͑sinusoidal amplitude modulated͒ in Co 2 ͑OH͒AsO 4 ͑Fig. 13͒.…”

“…The Co͑II͒ ions can be sited in two different octahedral and trigonal bipyramidal topologies. The edge-sharing ͓Co͑2͒O 4 ͑OH͒ 2 ͔ octahedra give rise to linear chains propagated along the c axis whereas the edge-sharing ͓Co͑1͒O 4 ͑OH͔͒ trigonal bipyramids constitute dimeric entities. The chain of octahedra, the dimeric unites, and the tetrahedral groups share corners thereby forming a threedimensional network.…”

“…11 The partial substitution of transition-metal ions in the structure severely affects the magnetic properties 14,15 giving rise to the evolution of the 3D antiferromagnetic system in the Co 2−x Cu x ͑OH͒PO 4 solid solution 15 up to a spin-gap system in the Cu 2 ͑OH͒PO 4 phase, 16 the spin-glasslike state in the ͑Co, Ni͒ 2 ͑OH͒PO 4 detected below 10 K, 14 or the higher ferromagnetic interactions at lower temperatures in Co 1.7 Mn 0.3 ͑OH͒PO 4 coexisting with a similar spin-glass state observed in the nonsubstituted cobalt hydroxy phosphate. 17 The similar ability of AsO 4 3− and PO 4 3− tetrahedra to stabilize anionic frameworks and the greater size of the AsO 4 3− anions predict some differences in the crystal packing features that could modify the complex magnetic properties exhibited in these phases. In this work, we present a deeper magnetic study of Co 2 ͑OH͒AsO 4 in order to determine ͑i͒ the nature of the main magnetic interactions and their anomalies, ͑ii͒ the magnetic structure of the low-temperature ordered phase, and ͑iii͒ the magnetic variations with respect to the isostructural Co 2 ͑OH͒PO 4 compound.…”

Metamagnetism and soliton excitations in the modulated ferromagnetic Ising chain CoV2O6

“…(The basic properties of the monoclinic polymorph have also recently been reported. 22 ) The structure of CoV 2 O 6 [ Fig. 1(a)] consists of well-separated edge-sharing chains of CoO 6 octahedra running down the b axis interspersed with nonmagnetic V 5+ in V 2 O 5 -like blocks.…”