Weak quasistatic magnetism in the frustrated Kondo lattice Pr2Ir2O7

Muon spin relaxation experiments have been performed in the pyrochlore iridate Pr2Ir2O7 for temperatures in the range 0.025–250K. Kubo–Toyabe relaxation functions are observed up to ≳200K, indicating static magnetism over this temperature range. The T→0 static muon spin relaxation rate Δ(0)≈8μs-1 implies a weak quasistatic moment (∼0.1μB). The temperature dependence of Δ is highly nonmean-field-like, decreasing smoothly by orders of magnitude but remaining nonzero for T