Crystal and Magnetic Structures and Magnetic Properties of Selenate Containing Natrochalcite, A^IM^II₂(H₃O₂)(SeO₄)₂Where A = Na or K and M = Mn, Co, or Ni

Abstract

The synthesis of a series of selenate containing natrochalcite, A(I)M(II)(2)(H(3)O(2))(SeO(4))(2) where A = Na or K and M = Mn, Co, or Ni (here labeled as AMH and AMD for the hydrogenated and deuterated compounds, respectively), the X-ray crystal structure determinations from single crystals (Ni) and powder (Mn), magnetic properties, and magnetic structures of the cobalt analogues are reported. The nuclear crystal structures for NaNiH, KNiH, and KMnH are similar to those reported for the cobalt analogues (NaCoH and KCoH) and consist of chains of edge-sharing octahedra (MO(6)) which are connected by H(3)O(2) and SeO(4) to form layers which are in turn bridged by the alkali, in an octahedral coordination site, to form the 3D-framework. The magnetic properties are characterized by antiferromagnetic interaction at high temperatures and antiferromagnetic ordering at low temperatures (NaCoH, 3.5 K; KCoH, 5.9 K; KNiH, 8.5 K; and KMnH, 16 K), except for KNi(2)(H(3)O(2))(SeO(4))(2) which displays a weak ferromagnetic interaction and no long-range ordering above 2 K. The neutron magnetic structures of the cobalt analogues, studied as a function of temperature, are different for the two cobalt salts and also different from all the known magnetic structures of the natrochalcite family. Whereas the magnetic structure of NaCoD has a k = (0, 0, 0), that of KCoD has one consisting of a doubled nuclear cell, k = (0, 0, 1/2). Both compounds have four magnetic sublattices related to the four cobalt atoms of the nuclear unit cell. In NaCoD the moments are in the bc-plane, M(y) = 2.51(2) μ(B) and M(z) = 1.29(4) μ(B), with the major component along the cobalt chain and the resultant moment, 2.83(3) μ(B), making an angle of 27° with the b-axis. The sum of the moments within the cell is zero. For KCoD the moment at each cobalt site has a component along each crystallographic axis, M(x) = 2.40(3), M(y) = 1.03(3), M(z) = 1.59(8) giving a total M = 2.49(3) μ(B). Within one nuclear cell the moments are fully compensated. The moments corresponding to the cobalt atoms of the second nuclear cell comprising the magnetic unit cell are oriented in opposite directions.

Analogous Chain Selenite Chlorides Ba2M(SeO3)2Cl2 (M = Cu2+, Ni2+, Co2+, Mn2+) and Pb2Cu(SeO3)2Cl2 with Tunable Spin S: Syntheses and Characterizations

“…However, these experimental systems are independent of different crystal structures. Isostructural 1D spin chain systems with different spin S have less been systematically investigated and discussed, despite there being several reports. − It is crucial to experimentally synthesize isostructural chain compounds with various spin values S for systematically investigating the quantum magnetism of 1D spin chain systems.…”

Layered Transition Metal Molybdates as New Slow-Release Micronutrient Fertilizer Matrices for Zn, Cu, and Mo

“…19,22−27 In addition, next to the class of LTMs, similar materials have been described, in which the Mo position is occupied by other elements, e.g., V or Se. 28,29 Here, LTM materials of Zn and/or Cu are proposed as promising new slow-release micronutrient fertilizer compounds. A sparingly soluble LTM material could guarantee a slow release of Mo and also supply accompanying cationic micronutrients Zn and Cu.…”

“…Two structural polytypes of the LTM material class have been identified, , i.e., one structure characterized by chains of edge-sharing transition metal octahedra interconnected by molybdate tetrahedra (referred to as the Φ x structure) and one structure characterized by sheets of edge-sharing transition metal octahedra with molybdate tetrahedra binding on cation vacancy sites (referred to as the Φ y structure). To date, LTM materials have been successfully synthesized with a range of divalent transition metals, including Zn, Cu, Ni, Co, and Mn. ,− In addition, next to the class of LTMs, similar materials have been described, in which the Mo position is occupied by other elements, e.g., V or Se. , …”

Observation of Spin Relaxation in a Vanadate Chloride with Quasi-One-Dimensional Linear Chain

“…In order to weaken the interchain interaction in 1D spin chain systems, one direct way is enlarging the interchain distance by the incorporation of nonmagnetic spacers. With this in mind, varieties of compounds with spin chain structures are established by applying nonmagnetic oxyanions as bridging units. ,,,− Vanadate anions are intriguing linkers to construct 1D magnetic compounds because of their wide variety of bridging modes. Vanadium atom can adopt various oxygen-coordination geometries such as VO 4 tetrahedron, VO 5 square pyramid or trigonal bipyramid, and VO 6 octahedron, providing a rich structural chemistry.…”