Spin liquid versus spin solid in A-site spinels

• Published in: Physica. B, Condensed matter Vol. 378; pp. 583 - 584
• Main Authors: Krimmel, A., Tsurkan, V., Sheptyakov, D., Loidl, A.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.2006; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Frustration; Magnetic properties and materials; Neutron scattering; Physics; Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source x-ray scattering, etc.); Spin liquids; Studies of specific magnetic materials; 61.12. - q; 75.25.+z; Spin liquids; 71.55.Jv; Neutron scattering; Frustration; Neutron diffraction; Spin fluctuations; Long-range order; 61.12.-q Spin liquids; Oxides; Neutron diffusion; Spin liquid; Spinels; Angular momentum; Spin state
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2006.01.413

Spinel compounds of stoichiometry AB 2 X 4 with magnetic A-site cations exhibit strong frustration effects. Frustration leads to strongly enhanced spin fluctuations that can easily suppress long range magnetic order (corresponding to a spin solid state) resulting in a dynamic spin liquid ground state. The same argument holds true for the orbital sector if an orbital moment is present. Neutron scattering is ideally suited to investigate the corresponding correlation functions. Here we present neutron diffraction studies on the A-site spinels MAl 2 O 4 ( M = Co , Fe, Mn). Whereas the Mn compound representing a spin-only system shows long range magnetic order below 42 K, the diffraction patterns of the Fe and Co spinel reveal a characteristic liquid structure factor of the magnetic scattering. This contrasting behavior can be related to the absence/presence of an orbital moment.