Electron paramagnetic resonance study of the f–d interaction in pyrochlore iridate Gd₂Ir₂O₇

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 .

Keywords:

• pyrochlore iridate
• electron paramagnetic resonance (EPR)
• f–d interaction

Notes

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the State Key Project of Fundamental Research of China [grant number 2010CB923403], [grant number 2011CBA00111]; the National Natural Science Foundation of China [grant number U1332140], [grant number U1232142], [grant number 11004196], [grant number 11174262], [grant number 11204288], [grant number 11574322].