Abstract
We present a detailed study on the magnetic order in the undoped mother compound LaFeAsO of the recently discovered Fe-based superconductor . In particular, we present local probe measurements of the magnetic properties of LaFeAsO by means of Mössbauer spectroscopy and muon-spin relaxation in zero external field along with magnetization and resistivity studies. These experiments prove a commensurate static magnetic order with a strongly reduced ordered moment of at the iron site below , well separated from a structural phase transition at . The temperature dependence of the sublattice magnetization is determined and compared to theory. Using a four-band spin density wave model both, the size of the order parameter and the quick saturation below are reproduced.
- Received 2 May 2008
DOI:https://doi.org/10.1103/PhysRevLett.101.077005
©2008 American Physical Society