Interpretation of isotope exchange data "without time": Nonisothermal exchange of dioxygen with oxides

As a result of transformation of isotope-exchange rate equations (isotope-kinetic equations), a relationship was derived that does not contain time and universally relates the variables of isotope composition (an isotope-mechanistic equation). With the use of this relationship, mechanistic parameters that characterize atomic rearrangements can be determined from experimental data even in cases when the rate of exchange varied in the course of a process, for example, under nonisothermal conditions. The use of the proposed approach for the treatment of the results of dynamic thermal isotope exchange in the O-2-YBa2Cu3Oy, and O-2-Pt/CeZrO systems demonstrated that the experimental data were excellently described by the theoretical equation derived in this work.