Structural distortions and magnetism in transition-metal cluster compound GaNb<sub>4</sub>Se<sub>8</sub>
ORAL
Abstract
Lacunar spinels AB4Q8 (A=Al, Ga, Ge; B=V, Nb, Mo, Ta; Q=S, Se) display a variety of novel phenomena including skyrmion lattices and pressure-induced insulator-metal transitions and superconductivity. The high temperature structure features unique tetrahedral transition-metal clusters with S=1/2 moments on an FCC lattice. Low temperature distortions of these clusters are crucial to the properties of lacunar spinels. In GaNb4Se8, antiferromagnetic interactions lead to geometric frustration and a magnetic transition associated with a tetragonal distortion, proposed to be a singlet state at low temperatures. We present results of structural characterization on lacunar spinel GaNb4Se8 under temperature and pressure in connection to its magnetic properties.
*This work was supported primarily by the NSF through the DMREF program DMR 1729489. The use of shared facilities from the Materials Research Science and Engineering Center (MRSEC) is gratefully acknowledged. The MRL Shared Experimental Facilities are supported by the MRSEC Program of the NSF under DMR 1720256; a member of the NSF-funded Materials Research Facilities Network (www.mrfn.org). J.L.Z also acknowledges the support of the NSF Graduate Research Fellowship Program under Grant No. 1650114.
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Presenters
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Julia L Zuo
- University of California, Santa Barbara