Abstract
The pyrochlore iridate has been investigated by means of the electron paramagnetic resonance spectroscopy. A magnetic transition at 20 K is found in addition to the transition at 130 K, which has not been reported previously. The phase transition at , which corresponds to a resistivity transition, is resulted from the long-range spin ordering of ions in all-in/all-out state. However, the magnetic transition at , which is regardless of resistivity transition, is not caused by but ions. Both of the magnetic transitions are irrelevant to the lattice distortion. We suggest that the competition between the enhanced paramagnetism of ions and the f–d interaction should be responsible for the magnetic transition at .
Notes
No potential conflict of interest was reported by the authors.