Schottky anomaly in Nd2CuO4 observed by muon spin relaxation

We report zero-field muon spin relaxation experiments on Nd₂CuO₄ focused on the low-temperature range for studying the Nd Schottky anomaly. In the magnetically ordered state we observed a significant increase and saturation of the muon spin precession frequency below T=15 K. A fit based on the temperature-dependent population of the Nd³⁺ Kramers ground-state doublet reveals a splitting of the doublet of Δ=4.2(6) K in good agreement with the work of Adelmann et al. [Phys. Rev. B 46, 3619 (1992)]. The same model was applied to account for the temperature dependence of the dynamic relaxation rate resulting in Δ=4.6(5) K. A quantitative evaluation of the temperature-dependent local magnetic field fluctuation rate is presented.