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  Skaugen, A.; Schierle, E.; van der Laan, G.; Shukla, D. K.; Walker, H. C.; Weschke, E.; Strempfer, J.: Long-range antiferromagnetic order of formally nonmagnetic Eu³⁺ Van Vleck ions observed in multiferroic Eu_1-xY_xMnO₃. Physical Review B 91 (2015), p. 180409/1-5

10.1103/PhysRevB.91.180409
Open Accesn Version

Abstract:
We report on resonant magnetic x-ray scattering and absorption spectroscopy studies of exchange-coupled antiferromagnetic ordering of Eu3+ magnetic moments in multiferroic Eu1−xYxMnO3 in the absence of an external magnetic field. The observed resonant spectrum is characteristic of a magnetically ordered 7F1 state that mirrors the Mn magnetic ordering, due to exchange coupling between the Eu 4f and Mn 3d spins. Here, we observe long-range magnetic order generated by exchange coupling of magnetic moments of formally nonmagnetic Van Vleck ions, which is a step further towards the realization of exotic phases induced by exchange coupling in systems entirely composed of non magnetic ions.