CONCERNING THE ABSTRACT “LATTICE DEFECTS IN SILVER BROMIDE”

In the third issue of volume XLVII of Uspekhi fizicheskikh nauk there was printed a short abstract (signed with the initials A. Kh.) under the title “Lattice Defects in Silver Bromide.”

Not considering it possible to enter, in “Letters to the Editor,” into a discussion of the problem under consideration as a whole, I nevertheless consider it absolutely necessary to point out certain defects of the abstract that may mislead the reader of UFN. The author, for example, writes: “The incorrect results (emphasized by me—A. M.) of earlier works\(^{5–7}\)**) (on isotope exchange—A. M.) are explained by the trivial case of dissolution and recrystallization of silver bromide.”

Let us note that under reference 6 there appears here the untimely deceased article of the laureate of the Stalin Prize, Professor Aleksandr Efimovich Polesitskii, whose results are quite correct, as, however, are probably also the experimental results of works 5 and 7. Lendzher’s works (reference 5), more precisely his second work (J. Chem. Phys. 11, 11 (1943)), contain an undoubtedly incorrect interpretation of experiments on exchange in the AgBr system (in the precipitate)—NaBr (in solution), but it is completely incomprehensible why A. E. Polesitskii is to blame for this, when in his work, written jointly with the author of the present letter (and evidently unknown to the abstractor), published in DAN 45, No. 6 (1944), he convincingly showed that the assumption of a diffusion mechanism of exchange by bromine ions in this system contradicts the data known to us on the num—

* See, for example, the textbook by L. D. Landau and E. M. Lifshitz, Quantum Mechanics, vol. 1 (p. 403).

** The reference numbers are given here according to the text of the abstract under discussion.

for the transfer of bromine and silver ions, the known values of the coefficients of electrical conductivity, etc. By the way, in this work, for the first time (and earlier by K. Wagner), a sufficiently complete theory was given for calculating the values of diffusion coefficients in the solid phase from exchange-experiment data, which one of the reviewers of Problems of Modern Physics (issue 10, p. 132, 1952) is evidently inclined, without any grounds, to ascribe to Hendricks.

Additional experiments on isotope exchange in the systems AgBr/Br⁻ and AgBr/Ag⁺, carried out (and published much earlier than the article cited in A. H.’s abstract under reference 11)*) with complete persuasiveness confirmed the point of view of A. E. Polesitsky, who maintained that exchange by bromine ions occurs only in the case of recrystallization of the silver bromide precipitate, whereas exchange by silver ions is quite possible and in a number of cases is unquestionably effected by direct exchange of solution ions with ions of the surface of the precipitate, with subsequent diffusion of the exchanging ions in the precipitate crystals.

A. Murin