Ordered spin-ice state in the geometrically frustrated metallic-ferromagnet Sm2Mo2O7

Surjeet Singh (1) , R. Suryanarayanan (1) , R. Tackett (2) , G. Lawes (2) , A. K. Sood (3) , P. Berthet (1) , A. Revcolevschi (1)

1 ICMMO - Institut de Chimie Moléculaire et des Matériaux d'Orsay
2 Department of Physics and Astronomy [Detroit]
3 Department of Physics [Bangalore]

The recent discovery of Spin-ice is a spectacular example of non-coplanar spin arrangements that can arise in the pyrochlore A2B2O7 structure. We present magnetic and thermodynamic studies on the metallic-ferromagnet pyrochlore Sm2Mo2O7. Our studies, carried out on oriented crystals, suggest that the Sm spins have an ordered spin-ice ground state below about T* = 15 K. The temperature- and field-evolution of the ordered spin-ice state are governed by an antiferromagnetic coupling between the Sm and Mo spins. We propose that as a consequence of a robust feature of this coupling, the tetrahedra aligned with the external field adopt a "1-in, 3-out" spin structure as opposed to "3-in, 1-out" in dipolar spin ices, as the field exceeds a critical value.

Domaines: Electrons fortement corrélés [cond-mat.str-el]; Science des matériaux [cond-mat.mtrl-sci]

Surjeet Singh, R. Suryanarayanan, R. Tackett, G. Lawes, A. K. Sood, et al.. Ordered spin-ice state in the geometrically frustrated metallic-ferromagnet Sm2Mo2O7. 2007. ⟨hal-00158081⟩