A variable temperature study of the crystal and magnetic structures of the giant magnetoresistant materials LnMnAsO (Ln = La, Nd)
arXiv:1207.0961 · doi:10.1103/PhysRevB.83.144429
Abstract
A variable temperature neutron and synchrotron diffraction study have been performed on the giant magnetoresistant oxypnictides LnMnAsO (Ln = La, Nd). The low temperature magnetic structures have been studied and results show a spin reorientation of the Mn2+ spins below TN (Nd) for NdMnAsO. The Mn2+ spins rotate from alignment along c to alignment into the basal plane and the Mn2+ and Nd3+ moments refine to 3.54(4) μB and 1.93(4) μB respectively at 2 K. In contrast there is no change in magnetic structure with temperature for LaMnAsO. There is no evidence of a structural transition down to 2 K, however discontinuities in the cell volume, Ln-O and Mn-As bond lengths are detected at \sim 150 K for both materials. This temperature coincides with the electronic transition previously reported and suggests a coupling between electronic and lattice degrees of freedom.
References in corpus (15)
- Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
- Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
- Superconductivity up to 37 K in (A1-xSrx)Fe2As2 with A=K and Cs
- Superconductivity and Phase Diagram in the Iron-based Arsenic-oxides ReFeAsO1-delta (Re = rare earth metal) without F-Doping
- Superconductivity at 25 K in hole doped
- Superconductivity at 52 K in iron-based F-doped layered quaternary compound Pr[O1-xFx]FeAs
- Superconductivity in Co-doped LaFeAsO
- Superconductivity in SrFe_(2-x)Co_xAs_2: Internal Doping of the Iron Arsenide Layers
- Bandwidth and Fermi surface of Iron-Oxypnictides: covalency and sensitivity to structural changes
- Itinerant Ferromagnetism in layered crystals LaCoOX (X = P, As)
- Renormalized behavior and proximity to a magnetic quantum critical point in BaCoAs
- Strong-coupling superconductivity in layered nickel-based LaOFNiAs
- Narrow superconducting window in Ni-doped LaFeAsO
- Nd induced Mn spin-reorientation transition in NdMnAsO
- Structural and electronic response upon hole-doping of rare-earth iron oxyarsenides Nd1-xSrxFeAsO (0 < x < 0.2)