We investigated the magnetic properties of pyrochlore ruthenates, R2Ru2O7, by using the muon spin relaxation (μSR) method. The appearance of a magnetically ordered state was confirmed below 145 K by observing the decrease in the initial asymmetry of the muon-spin polarization. This was due to a long-range ordering of Ru4+ spins. An additional anomaly in the μSR time spectrum was observed around 30 K. A part of the lost initial asymmetry was recovered and gradually decreases again with decreasing temperature below 30 K. This anomaly was supposed to be due to a magnetic ordering of Nd3+ spins which was coupled with ordered Ir moment via the 3d-4f exchange interaction.
Fully filling-controlled pyrochlore ruthenates: Emergent ferromagnetic-metal state and geometrical Hall effect
