Nonadiabatic Quantum Theory of Interstitial Diffusion in Crystals

Pavlovich, V. N.; Rudko, V. N.

doi:10.1002/pssb.2220880205

Cited by 6 publications

(1 citation statement)

References 6 publications

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“…The displacement dependence is incorporated in a step function model in .Ipp, for a FCC lattice. Since then Kagan and Klinger (1976) and Pavlovich and Rudko (1978) emphasised the strain dependence ofJp,, .…”

Section: Introductionmentioning

confidence: 99%

N.N. Bogolyubov and the scattering matrix

Medvedev¹

1994

Russ. Math. Surv.

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The quantum diffusion of H. D. T and p + in copper is studied. The impurity-host configurational interaction is evaluated according to the prescriptions of Teichler. The impurity is represented as a Gaussian wave packet and the total transition probability is evaluated explicitly at low. high and intermediate temperatures across a piecewise quadratic potential barrier. It is found that the tunnelling transitions dominate at low temperatures while over-barrier transitions dominate at high temperatures. The characteristic transition temperature for p + i n C u is found to be in good agreement with the experimental value. The WT-o diffusion path is adopted for H, D and T and the 0-0 path for p + diffusion. The contribution of excited states in the respective potential wells is also included. The calculated pre-exponential factors Do and migration energies E , are found to be in good agreement with the experimental values wherever available. An inverse isotope dependence in D o and E , is found abo1.e T = 250 K while it is absent at low temperatures. D O and E , are also reported for the intermediate temperature range.

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Section: Introductionmentioning

confidence: 99%

N.N. Bogolyubov and the scattering matrix

Medvedev¹

1994

Russ. Math. Surv.

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Theory of Multi‐Phonon Transitions beyond the Condon Approximation

Teichler

1981

Physica Status Solidi (b)

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For light interstitials in deformable host-materials ("small-polaron"-like systems) the theory of multi-phonon transitions is developed beyond the so-called Condon approximation, i.e., the effect of phonon fluctuations on the defect transfer-integrals J is explicitly taken into account. In particular the rate of incoherent defect transitions is evaluated up to second order in J and the temperature dependence of the multi-phonon processes is discussed in the regime above half of the Debye temperature.Fur leichte Zwischengitterteilchen in deformierbaren Wirtsmaterialien (Systeme vom Typ des kleinen Polarons) wird die Theorie der Viel-Phononen-Ubergange jenseits der sogenannten CondonNiiherung entwickelt, d. h., die Auswirkungen der Fluktuationen des Phononensystems auf die Ubergangs-Integrale J des Defekts werden explizit berucksichtigt. Insbesondere wird die Rate der inkoharenten Uberglnge in zweiter Ordnung in J bestimmt und die Temperaturabhangigkeit der VieI-Phononen-Prozesse im Bereich oberhalb der halben Debye-Temperatur diskutiert.

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Enhanced Diffusion of Impurities and Defects in Crystals in Conditions of Ultrasonic and Radiative Excitation of the Crystal Lattice

Pavlovich¹

1993

Physica Status Solidi (b)

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On the basis of the quantum theory of diffusion the influence of crystal lattice excitations (ultrasonic, nuclear irradiation) on the diffusion of impurity atoms is analysed. The effects considered in the paper are determined by two factors: the change of population of the impurity oscillator levels due to interaction with nonequilibrium excitations of the crystal lattice, and the change of the probability of diffusion transitions on the given level. The effects are qualitatively different for heavy impurity atoms whose diffusion is enhanced in nonequilibrium conditions and for light impurity atoms for which the effect of additional localization is possible. Ha OCHOBC KBaHTOBOfi ,4M@$Y3HH IIpOBeAeH aHaJIA3 BJIHRHHX B o 3 6 y~~e H~f i KpHCTaJIJIHYeCKOfi PeIIICTKA (yJIhTpa3ByK, XAepHOe 0 6 n y s e~~e ) Ha ,4A@$Y3HK) IIpHMKHhIX BTOMOB. PaCcMOTpeHHbIe B pa6OTe 3@$eKTbl OIIpeAeJIXIoTCX AByMR @KTOpaMA: A3MeHeHHeM 3aceJIeHHOCTefi YpOBHefi npMMeCHOr0 OCqHJIJIRTOpa, 6naronap~ B3aHMOnefiCTBHW C HePaBHOBeCHhlMA KOJIe6aHHRMA KpHCTaJIJIAYecKOfi PeIIIeTKH, H A3MeHeHHeM BepOXTHOCTA nH@$y3AOHHOrO IIepeXOna IIO AaHHOMY YPOBHIO. 3@@KTbI

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Nonadiabatic Quantum Theory of Interstitial Diffusion in Crystals

Cited by 6 publications

References 6 publications

N.N. Bogolyubov and the scattering matrix

N.N. Bogolyubov and the scattering matrix

Theory of Multi‐Phonon Transitions beyond the Condon Approximation

Enhanced Diffusion of Impurities and Defects in Crystals in Conditions of Ultrasonic and Radiative Excitation of the Crystal Lattice

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