Spin-gap opening accompanied by a strong magnetoelastic response in the S=1 magnetic dimer system Ba3BiRu2O9
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Date
2011-12-15
Journal Title
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Publisher
American Physical Society
Abstract
Neutron diffraction, magnetization, resistivity, and heat-capacity measurements on the 6H-perovskite Ba3BiRu2O9 reveal simultaneous magnetic and structural dimerization driven by strong magnetoelastic coupling. An isostructural but strongly displacive first-order transition on cooling through T∗=176 K is associated with a change in the nature of direct Ru–Ru bonds within Ru2O9 face-sharing octahedra. Above T∗, Ba3BiRu2O9 is an S=1 magnetic dimer system with intradimer exchange interactions J0/kB=320 K and interdimer exchange interactions J′/kB=−160 K. Below T∗, a spin-gapped state emerges with Δ≈220 K. Ab initio calculations confirm antiferromagnetic exchange within dimers, but the transition is not accompanied by long-range magnetic order. ©2011 American Physical Society
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Keywords
Neutron diffraction, Specific heat, Magnetic properties, Phase transformations, Exchange interactions, Antiferromagnetism
Citation
Miiller, W., Avdeev, M., Zhou, Q., Studer, A. J., Kennedy, B. J., Kearley, G. J., & Ling, C. D. (2011) Spin-gap opening accompanied by a strong magnetoelastic response in the S=1 magnetic dimer system Ba3BiRu2O9. Physical Review B, 84(22), 220406. doi:10.1103/PhysRevB.84.220406