Abstract
Muon spin rotation and relaxation (SR) experiments have been carried out to characterize magnetic and superconducting ground states in the alloy series. In the ferromagnetic end compound the spontaneous local field at positive-muon () sites below the ordering temperature is greater than expected from dipolar coupling to ferromagnetically aligned Nd moments, indicating an additional indirect RKKY-like transferred hyperfine mechanism. For , spin relaxation rates in zero and weak longitudinal applied fields indicate that static fields at sites below are reduced and strongly disordered. We argue this is unlikely to be due to reduction of Nd moments, and speculate that the Nd- interaction is suppressed and disordered by Pr doping. In an sample, which is superconducting below K, there is no sign of “spin freezing” (static Nd magnetism), ordered or disordered, down to 25 mK. Dynamic spin relaxation is strong, indicating significant Nd-moment fluctuations. The diamagnetic frequency shift and spin relaxation in the superconducting vortex-lattice phase decrease slowly below , suggesting pair breaking and/or possible modification of Fermi-liquid renormalization by Nd spin fluctuations. For , the SR data provide evidence against phase separation; superconductivity and Nd magnetism coexist on the atomic scale.
10 More- Received 27 February 2014
- Revised 3 April 2014
DOI:https://doi.org/10.1103/PhysRevB.89.144419
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