TY - JOUR
T1 - Glassy behavior and isolated spin dimers in a new frustrated magnet BaCr9pGa12-9pO19
AU - Yang, Junjie
AU - Samarakoon, Anjana M.
AU - Hong, Kyun Woo
AU - Copley, John R.D.
AU - Huang, Qingzhen
AU - Tennant, Alan
AU - Sato, Taku J.
AU - Lee, Seung Hun
N1 - Funding Information:
AS is supported by Oak Ridge National Laboratory. The work at NIST Center for Neutron Research (NCNR) was supported in part by the NSF under Agreement DMR-1508249. The identification of any commercial product or trade name does not imply endorsement or recommendation by the NIST.
Publisher Copyright:
©2016 The Physical Society of Japan.
PY - 2016/9/15
Y1 - 2016/9/15
N2 - Using bulk susceptibility and neutron scattering techniques, we have studied a new frustrated magnet, BaCr9pGa12-9pO19 [BCGO(p)], with 0.4 ≲ p ≲ 0.9. This system is isostructural to SrCr9pGa12-9pO19 [SCGO(p)], in which the magnetic Cr3+ (3d3, s = 3/2) ions form a quasi-two-dimensional triangular lattice of bi-pyramids or kagome-triangle-kagome trilayers. Our bulk susceptibility data exhibit glassy behavior at temperatures much lower than the absolute values of the Curie-Weiss temperature ΘCW ≈ -695(1) K for BCGO(p = 0.902(8)). The frustration index |ΘCW|/Tf is as high as 190 for BCGO(p = 0.902(8)) indicating strong frustration. Our inelastic neutron scattering data on BCGO(p = 0.902(8)) reveal a dispersionless magnetic excitation centered at ℏω = 16.5(1) meV, due to a singlet to triplet excitation of spin s = 3/2 dimers. The spin dimers are formed by Cr3+ ions in two 4fvi layers that lie between 12k-2a-12k (kagome-triangle-kagome) trilayers. These results indicate that BCGO(p) is another good candidate system for a strongly frustrated quasi-two-dimensional magnet.
AB - Using bulk susceptibility and neutron scattering techniques, we have studied a new frustrated magnet, BaCr9pGa12-9pO19 [BCGO(p)], with 0.4 ≲ p ≲ 0.9. This system is isostructural to SrCr9pGa12-9pO19 [SCGO(p)], in which the magnetic Cr3+ (3d3, s = 3/2) ions form a quasi-two-dimensional triangular lattice of bi-pyramids or kagome-triangle-kagome trilayers. Our bulk susceptibility data exhibit glassy behavior at temperatures much lower than the absolute values of the Curie-Weiss temperature ΘCW ≈ -695(1) K for BCGO(p = 0.902(8)). The frustration index |ΘCW|/Tf is as high as 190 for BCGO(p = 0.902(8)) indicating strong frustration. Our inelastic neutron scattering data on BCGO(p = 0.902(8)) reveal a dispersionless magnetic excitation centered at ℏω = 16.5(1) meV, due to a singlet to triplet excitation of spin s = 3/2 dimers. The spin dimers are formed by Cr3+ ions in two 4fvi layers that lie between 12k-2a-12k (kagome-triangle-kagome) trilayers. These results indicate that BCGO(p) is another good candidate system for a strongly frustrated quasi-two-dimensional magnet.
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U2 - 10.7566/JPSJ.85.094712
DO - 10.7566/JPSJ.85.094712
M3 - Article
AN - SCOPUS:84984879092
SN - 0031-9015
VL - 85
JO - Journal of the Physical Society of Japan
JF - Journal of the Physical Society of Japan
IS - 9
M1 - 094712
ER -