Research Output
Ba8MnNb6O24: A model two-dimensional spin-5/2 triangular lattice antiferromagnet
  We successfully synthesized and characterized the triangular lattice antiferromagnet Ba8MnNb6O24, which comprises equilateral spin-5/2Mn2+ triangular layers separated by six nonmagnetic Nb5+ layers. The detailed susceptibility, specific heat, elastic and inelastic neutron scattering measurements, and spin-wave theory simulation on this system reveal that it has a 120∘ ordering ground state below TN=1.45K with in-plane nearest-neighbor exchange interaction ≈0.11meV. While the large separation 18.9 Å between magnetic layers makes the interlayer exchange interaction virtually zero, our results suggest that a weak easy-plane anisotropy is the driving force for the km=(1/3,1/3,0) magnetic ordering. The magnetic properties of Ba8MnNb6O24, along with its classical excitation spectra, contrast with the related triple perovskite Ba3MnNb2O9, which shows easy-axis anisotropy, and the isostructural compound Ba8CoNb6O24, in which the effective spin-1/2Co2+ spins do not order down to 60 mK and in which the spin dynamics shows signs of strong quantum effects.

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    28 May 2019

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    American Physical Society (APS)

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Rawl, R., Ge, L., Lu, Z., Evenson, Z., Dela Cruz, C. R., Huang, Q., …Ma, J. (2019). Ba8MnNb6O24: A model two-dimensional spin-5/2 triangular lattice antiferromagnet. Physical Review Materials, 3(5),


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