HPCAT

at the Advanced Photon Source

Colossal Density-Driven Resistance Response in MnS2

Image of MnS2
Increased charge-sharing between Mn (circles) metal and S2 (dumbbell) ligands from (L—R) 0—40 GPa.

A recently published article reports a colossal resistance drop spanning eight orders of magnitude in manganese disulfide – MnS2 – as compression to moderate pressures of 12 GPa drives the material into a metallic state. This is one of the largest-known density-driven drops in resistance within a single crystallographic phase – measured by powder X-ray diffraction at HPCAT 16-ID-B.

The metallic transition is driven by a previously unidentified mechanism in which metal d states overlap with unoccupied ligand p states, as opposed to the more typical ligand-to-metal charge transfer, and is unique to anions with unsaturated valences. In principle, this mechanism could be common among materials with a combination of strongly-correlated metal cations and molecular anions.

Figure 1 - MnS2 at room temperature
Figure 1 - Four-probe electrical resistance measures across MnS2 at room-temperature with 8 orders of magnitude decrease in resistance at 12 GPa.
Figure 2 - Powder X-ray diffraction measurements
Figure 2 - Powder X-ray diffraction measurements from 16-ID-B showing transition from pyrite-like to arsenopyrite structures in MnS2 on compression at room-temperature.

 

The work was led by undergraduate researcher, Dylan Durkee of University of Nevada Las Vegas, who is now pursuing postgraduate studies at University of Rochester with SSAA partner, Ranga Dias.

For more, see: Colossal Density-Driven Resistance Response in the Negative Charge Transfer Insulator MnS2. Dylan Durkee, Nathan Dasenbrock-Gammon, G. Alexander Smith, Elliot Snider, Dean Smith, Christian Childs, Simon A. J. Kimber, Keith V. Lawler, Ranga P. Dias, and Ashkan Salamat, Phys. Rev. Lett. 127, 016401 – Published 30 June 2021

 

 

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