Abstract
Neutron diffraction and muon spin relaxation measurements are used to obtain a detailed phase diagram of . The isoelectronic substitution of Ru for Fe acts effectively as spin dilution, suppressing both the structural and magnetic phase transitions. The temperature of the tetragonal-orthorhombic structural phase transition decreases gradually as a function of . Slightly below , coherent precessions of the muon spin are observed corresponding to static magnetism, possibly reflecting a significant magnetoelastic coupling in the FeAs layers. Short-range order in both the Fe and Pr moments persists for higher levels of . The static magnetic moments disappear at a concentration coincident with that expected for percolation of the square-lattice model.
1 More- Received 11 July 2014
- Revised 7 August 2014
DOI:https://doi.org/10.1103/PhysRevB.90.064515
©2014 American Physical Society