Possible valence-bond condensation in the frustrated cluster magnet LiZn2Mo3O8

• Published in: Nature materials 2012-06, Vol.11 (6), p.493-496
• Main Authors: Sheckelton, J. P., Neilson, J. R., Soltan, D. G., McQueen, T. M.
• Format: Article
• Language: English
• Subjects: 639/301/119/997; 639/301/930/1032; 639/301/930/12; Biomaterials; Chemical compounds; Chemical synthesis; Chemistry and Materials Science; Condensed Matter Physics; Ions; letter; Magnetic properties; Magnetism; Materials Science; Nanotechnology; Optical and Electronic Materials; Solids
• ISSN: 1476-1122; 1476-4660
• DOI: 10.1038/nmat3329

Geometrically frustrated magnets are systems where it is impossible for all magnetic interactions to occur simultaneously. The discovery of frustrated magnetism in a system where the magnetic moments are situated across clusters of transition-metal elements instead of individual ions promises a new approach for controlling such magnetic states. The emergence of complex electronic behaviour from simple ingredients has resulted in the discovery of numerous states of matter. Many examples are found in systems exhibiting geometric magnetic frustration, which prevents simultaneous satisfaction of all magnetic interactions. This frustration gives rise to complex magnetic properties such as chiral spin structures 1 , 2 , 3 , orbitally driven magnetism 4 , spin-ice behaviour 5 exhibiting Dirac strings with magnetic monopoles 6 , valence-bond solids 7 , 8 and spin liquids 9 , 10 . Here we report the synthesis and characterization of LiZn 2 Mo 3 O 8 , a geometrically frustrated antiferromagnet in which the magnetic moments are localized on small transition-metal clusters rather than individual ions 11 , 12 , 13 . By doing so, first-order Jahn–Teller instabilities and orbital ordering are prevented, allowing the strongly interacting magnetic clusters in LiZn 2 Mo 3 O 8 to probably give rise to an exotic condensed valence-bond ground state reminiscent of the proposed resonating valence-bond state 14 , 15 . Our results also link magnetism on clusters to geometric magnetic frustration in extended solids, demonstrating a new approach for unparalleled chemical control and tunability in the search for collective, emergent electronic statesof matter 16 , 17 .