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

TL;DR

This study reveals an ordered spin-ice state in the metallic ferromagnet Sm2Mo2O7, showing unique spin arrangements influenced by Sm-Mo coupling, with potential implications for understanding frustrated magnetic systems.

Contribution

It demonstrates the existence of an ordered spin-ice ground state in a metallic pyrochlore, highlighting the role of Sm-Mo coupling in shaping spin configurations.

Findings

Ordered spin-ice state below 15 K

Field-induced transition to '1-in, 3-out' structure

Antiferromagnetic Sm-Mo coupling influences spin arrangements

Abstract

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.