Tunneling chemical exchange reaction $ extrm{D}+ extrm{HD}
ightarrow extrm{D}_{2}+ extrm{H}$ in solid HD and D$_2$ at temperatures below 1$,$K Academic Article uri icon

abstract

  • We report on a study of the exchange tunneling reaction D+HD$
    ightarrow$D$_{2}$+H in a pure solid HD matrix and in a D$_{2}$ matrix with 0.23$\%$ HD admixture at temperatures between 130$,$mK and 1.5$,$K. We found that the exchange reaction rates, $k_{exHD}sim3 imes10^{-27}$cm$^{3}$s$^{-1}$ in the pure HD matrix, and $k_{exD_{2}}=9(4) imes10^{-28}$cm$^{-3}$ in the D$_{2}$ matrix are nearly independent of temperature within this range. This confirms quantum tunnelling nature of these reactions, and their ability to proceed at temperatures down to absolute zero. Based on these observations we concluded that exchange tunneling reaction H+H$_{2}
    ightarrow$H$_{2}$+H should also proceed in a H$_{2}$ matrix at the lowest temperatures. On contrary, the recombination of H atoms in solid H$_{2}$ and D atoms in solid D$_{2}$ is substantially suppressed at the lowest temperatures as a result of increasing of violation for resonance tunneling of atoms when they approach each other.

author list (cited authors)

  • Sheludiakov, S., Ahokas, J., Jrvinen, J., Zvezdov, D., Lehtonen, L., Vainio, O., ... Khmelenko, V. V.

publication date

  • January 2015