Citation for published item:nD finghi nd ulD evijit uumr nd unungoD udipt nd eehuisD wnfred nd roserD endres nd ¤ oensD hniel wF nd hnelleD lter nd illimsD oert gF nd vnsterD om nd ioD pn nd w¤ ollerD tohnnes F nd flundellD tephen tF nd ryesD illim nd pelser D gludi nd tnsenD wrtin @PHIRA 9vttieEsiteEspei( spin dynmis in doule perovskite rPgoysyTF9D hysil review lettersFD IIP @IRAF pF IRUPHPF Further information on publisher's website: eprinted with permission from the emerin hysil oietyX finghi nD evijit uumr ulD udipt unungoD wnfred eehuisD endres roserD hniel wF ¤ oensD lter hnelleD oert gF illimsD om vnsterD pn ioD tohnnes F w¤ ollerD tephen tF flundellD illim ryesD gludi pelserD nd wrtin tnsenD hysil eview vettersD IIPD IRUPHPD PHIRF PHIR y the emerin hysil oietyF eders my viewD rowseD ndGor downlod mteril for temporry opying purposes onlyD provided these uses re for nonommeril personl purposesF ixept s provided y lwD this mteril my not e further reproduedD distriutedD trnsmittedD modi(edD dptedD performedD displyedD pulishedD or sold in whole or prtD without prior written permission from the emerin hysil oietyF
Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Magnetic properties and spin dynamics have been studied for the structurally ordered double perovskite Sr 2 CoOsO 6 . Neutron diffraction, muon-spin relaxation, and ac-susceptibility measurements reveal two antiferromagnetic (AFM) phases on cooling from room temperature down to 2 K. In the first AFM phase, with transition temperature T N1 ¼ 108 K, cobalt (3d 7 , S ¼ 3=2) and osmium (5d 2 , S ¼ 1) moments fluctuate dynamically, while their average effective moments undergo long-range order. In the second AFM phase below T N2 ¼ 67 K, cobalt moments first become frozen and induce a noncollinear spin-canted AFM state, while dynamically fluctuating osmium moments are later frozen into a randomly canted state at T ≈ 5 K. Ab initio calculations indicate that the effective exchange coupling between cobalt and osmium sites is rather weak, so that cobalt and osmium sublattices exhibit different ground states and spin dynamics, making Sr 2 CoOsO 6 distinct from previously reported double-perovskite compounds.
The accurate electron density distribution and magnetic properties of two metal−organic polymeric magnets, the quasi-onedimensional (1D) Cu(pyz)(NO 3 ) 2 and the quasi-two-dimensional (2D) [Cu(pyz) 2 (NO 3 )]NO 3 •H 2 O, have been investigated by high-resolution single-crystal X-ray diffraction and density functional theory calculations on the whole periodic systems and on selected fragments. Topological analyses, based on quantum theory of atoms in molecules, enabled the characterization of possible magnetic exchange pathways and the establishment of relationships between the electron (charge and spin) densities and the exchange-coupling constants. In both compounds, the experimentally observed antiferromagnetic coupling can be quantitatively explained by the Cu−Cu superexchange pathway mediated by the pyrazine bridging ligands, via a σ-type interaction. From topological analyses of experimental charge-density data, we show for the first time that the pyrazine tilt angle does not play a role in determining the strength of the magnetic interaction. Taken in combination with molecular orbital analysis and spin density calculations, we find a synergistic relationship between spin delocalization and spin polarization mechanisms and that both determine the bulk magnetic behavior of these Cu(II)-pyz coordination polymers.
We present the results of muon-spin relaxation measurements of spin excitations in the onedimensional quantum Heisenberg antiferromagnet Cu(pyz)(NO3)2. Using density-functional theory we propose muon sites and assess the degree of perturbation the muon probe causes on the system. We identify a site involving the muon forming a hydroxyl-type bond with an oxygen on the nitrate group that is sensitive to the characteristic spin dynamics of the system. Our measurements of the spin dynamics show that in the temperature range TN < T < J (between the ordering temperature TN and the exchange energy scale J) the field-dependent muon spin relaxation is characteristic of diffusive transport of spin excitations over a wide range of applied fields. We also identify a possible crossover at higher applied fields in the muon probe's response to the fluctuation spectrum, to a regime where the muon detects early-time transport with a ballistic character. This behavior is contrasted with that found for T > J and that in the related two-dimensional system Cu(pyz)2(ClO4)2.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.