The 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.

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.

A series of strontium vanadium oxide-hydride phases prepared by utilizing a low-temperature synthesis strategy in which oxide ions in Sr(n+1)V(n)O(3n+1) (n=∞, 1, 2) phases are topochemically replaced by hydride ions to form SrVO2H, Sr2VO3H, and Sr3V2O5H2, respectively. These new phases contain sheets or chains of apex-linked V(3+)O4 squares stacked with SrH layers/chains, such that the n=∞ member, SrVO2H, can be considered to be analogous to "infinite-layer" phases, such as Sr(1-x)Ca(x)CuO2 (the parent phase of the high-T(c) cuprate superconductors), but with a d(2) electron count. All three oxide-hydride phases exhibit strong antiferromagnetic coupling, with SrVO2H exhibiting an antiferromagnetic ordering temperature, T(N)>300 K. The strong antiferromagnetic couplings are surprising given they appear to arise from π-type magnetic exchange.

One of the most fundamental limitations of a muon-spin relaxation experiment can be the lack of knowledge of the implantation site of the muon and the uncertainty about the muon's perturbation of its host. Here we review some of the work done on the 'muon site problem' in the solid state and highlight some recent applications of electronic structure calculations that have successfully characterized the quantum states of muons in a number of insulating compounds containing fluorine, in a number of pnictide superconductors, and in ZnO. arXiv:1307.0651v1 [cond-mat.str-el]

The interplay and coexistence of superconducting, magnetic and structural order parameters in NaFe1−xCoxAs has been studied using SQUID magnetometry, muon-spin rotation and synchrotron x-ray powder diffraction. Substituting Fe by Co weakens the ordered magnetic state through both a suppression of TN and a reduction in the size of the ordered moment. Upon further substitution of Fe by Co the high sensitivity of the muon as a local magnetic probe reveals a magnetically disordered phase, in which the size of the moment continues to decrease and falls to zero around the same point at which the magnetically-driven structural distortion is no longer resolvable. Both magnetism and the structural distortion are weakened as the robust superconducting state is established.