Transverse field μ+ SR-measurements on a single crystal sample of U2Zn17 reveal a strikingly non uniform magnetic behavior. While part (∼30%) of the U-5f moments remain paramagnetic below TN = 9.7 K (at least for external fields ≥0.2 T) another part (∼20%) enters into a complex order below 9.7 K which is associated with huge internal field spreads at the μ+ sites. Above TN this part causes an anisotropic μ+ Knight shift involving direction cosines up to 8th order. Only. the remaining fraction is compatible with the simple AF order suggested by neutron diffraction studies. © 1992.

The 1-K phase transition in UCu5, showing up in specific-heat data within the antiferromagnetic state below TN 15 K, was investigated. Neither the average internal fields seen by the + nor the magnetic and nuclear Bragg reflections in the neutron-diffraction data reflect the phase transition while the muon relaxation rates increase drastically below 1.2 K. These results are interpreted in terms of some additional small-moment magnetic order or spin-density-wave phenomenon, implying the coexistence of two rather independent electronic subsystems, one involving eeheavyee electrons, associated with the weak magnetism, and the other associated with the eeconventionalee antiferromagnetic order. © 1990 The American Physical Society.

We report specific heat and μSR measurements on Th (x =0.019) and/or B (y=0.03) substituted UBe13. The specific heat data show that either Th or B substitution reduces the Kondo temperature TK and increases the entropy at the superconducting transition by almost 20%, indicating an enhanced density of states. However, whereas μSR shows clear evidence for magnetic correlations for Th substitutions (0.019