Magnetic Properties and Magnetic Structures of Synthetic Natrochalcites, Na[supII][sub2](D[sub3]O[sub2])(MoO[sub4])[sub2], M = Co or Ni.
Abstract: The magnetic properties and magnetic structures from neutron diffraction of two synthetic natrochalcites, NaM[supII][sub2](H[sub3]O[sub2])(MoO[sub4])[sub2], M = Co (1Co) or Ni (2Ni), are reported. They are isostructural (monoclinic C2/m) and consist of chains of edge-shared MO[sub6] octahe...
| Publicado en: | Journal of the American Chemical Society Vol. 130; no. 40; pp. 13490 - 13500 |
|---|---|
| Autores principales: | , , , , , |
| Formato: | Artículo |
| Publicado: |
American Chemical Society
10/8/2008
|
| Materias: | |
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=34840834&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 34840834 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 10/8/2008 vid: 130 iid: 40 pid: 997 pub: American Chemical Society artinfo: ui: 34840834 10.1021/ja804685u ppf: 13490 ppct: 10 formats: tig: atl: Magnetic Properties and Magnetic Structures of Synthetic Natrochalcites, Na[supII][sub2](D[sub3]O[sub2])(MoO[sub4])[sub2], M = Co or Ni. aug: au: Vilminot, Serge André, Gilles Bouree-Vigneron, Francoise Baker, Peter J. BIundeII, Stephen J. Kurmoo, Mohamedally affil: Groupe des Matériawc Inorganiques, IPCMS, UMR 7504 CNRS- ULP, 23 rue du Loess, BP 43, 67034 Strasbourg Cedex 2, France Laboratoire Leon Brillouin, CEA-CNRS, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom Laboratoire de Chimie de Coordination Organique, CNRS-UMR7I4O, Université Louis Pasteur, Institut Le Be!, 4 rue Blaise Pascal, 67000 Strasbourg Cedex 01, France su: Antiferromagnetism Nickel Cobalt Metal ions Optical diffraction Entropy Magnetic properties sug: subj: Antiferromagnetism Nickel Cobalt Metal ions Optical diffraction Entropy Magnetic properties ab: Abstract: The magnetic properties and magnetic structures from neutron diffraction of two synthetic natrochalcites, NaM[supII][sub2](H[sub3]O[sub2])(MoO[sub4])[sub2], M = Co (1Co) or Ni (2Ni), are reported. They are isostructural (monoclinic C2/m) and consist of chains of edge-shared MO[sub6] octahedra connected by μ-O from H[sub3]O[sub2] and MoO[sub4][sup2-]. These chains form a three-dimensional network with O-H-O, O-Mo-O, and O-Na--O bridging 4, 3, and 4 metal ions, respectively. Both compounds behave as canted antiferromagnets but differ in their behaviors, 1Co showing a broad maximum (28 K) above the Néel transition (21 K) and the canting taking place at 13K, some 8 K below T[subN], while for 2Ni the canting takes place at T[subN] (28 K). Analyses of the neutron powder diffraction data shed some light on the geometry of D[sub3]O[sub2][sup-] and suggest antiferromagnetism with a propagation vector k = (0,0,0) with the moments within each chain being parallel but antiparallel to those in neighboring chains. The difference between 1 Co and 2Ni is in the orientation of the moments; they are parallel to the chain axis (b-axis) for iCo and perpendicular to it for 2Ni with a major component along the c-axis and a small one along the a-axis. The heat capacity data peak at 20.9(3) K (1 Co) and 25.1(1) K (2Ni). The derived magnetic entropies, following correction of the lattice contribution using the measured data for the nonmagnetic Zn analogue, suggest S = 1/2 for 1Co but is lower than that expected for 2Ni (S = 1). In both cases, only Ca. 60% of the entropy is found below the magnetic ordering temperature, suggesting considerable short-range correlations at higher temperatures. While the temperature at which the magnetic diffraction becomes observable coincides with that of at the peak in heat capacity, it is lower than T[subN] observed by magnetization measurements in both cases, and there is evidence of short- range ordering in a narrow range of temperature (T[subN] ± 5 K). pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2008 holdings: @attributes: islocal: N |
|---|