JETP Letters: issues online

$The diffusion coefficient of negative charges, D _ , falls off monotonically in hep p-K2 crystals over the temperature interval 13.6-5.8 K. At T> 10 K, the value of D is close to the self-diffusion coefficient Dp in the region of a thermally activated motion of the molecules. The typical activation energies for charges, Δ _ , and for molecules, As, are nearly twice as large as the known vacancy formation energy Ett. Below 8 Κ, Δ _ is essentially the same as Ev. This result confirms an earlier suggestion {A. A. Levchenko and L. P. Mezhov-Deglin, Zh. Eksp. Teor. Fiz. 98, 349 (1990) [Sov. Phys. JETP 71,196 (1990) ]} that the motion of negative charges inp-H2 is controlled by a vacancy mechanism. It also supports the earlier theoretical suggestion [ C. Ebner and С. C. Sung, Phys. Rev. В 5,2625 (1972) ] that the vacancy diffusion mechanism changes from a classical thermally activated mechanism to a quantum-mechanical tunneling as the temperature is lowered.$

The diffusion coefficient of negative charges, D _ , falls off monotonically in hep p-K₂ crystals over the temperature interval 13.6-5.8 K. At T> 10 K, the value of D is close to the self-diffusion coefficient D_p in the region of a thermally activated motion of the molecules. The typical activation energies for charges, Δ _ , and for molecules, A_s, are nearly twice as large as the known vacancy formation energy E_tt. Below 8 Κ, Δ _ is essentially the same as E_v. This result confirms an earlier suggestion {A. A. Levchenko and L. P. Mezhov-Deglin, Zh. Eksp. Teor. Fiz. 98, 349 (1990) [Sov. Phys. JETP 71,196 (1990) ]} that the motion of negative charges inp-H₂ is controlled by a vacancy mechanism. It also supports the earlier theoretical suggestion [ C. Ebner and С. C. Sung, Phys. Rev. В 5,2625 (1972) ] that the vacancy diffusion mechanism changes from a classical thermally activated mechanism to a quantum-mechanical tunneling as the temperature is lowered.