Low-temperature energy release in platinum after ion radiation

The release of stored energy and the change of resistivity were measured simultaneously in the same specimen during the annealing from 15 to 35 K of platinum irradiated with 20-MeV deuterons. The calorimeter and differential power analysis used are described in detail. The work was undertaken to determine whether the enhanced initial rate of resistivity increase during the irradiation of quenched platinum, as compared to the rate in annealed platinum, results from greater Frenkel-pair production or a larger Frenkel resistivity in the quenched material. The results indicate that most of the enhancement in these irradiations represents increased production. The resistivity increment per defect added by the irradiation when measured at 5 K is increased only a few percent by the vacancies from the quench. The additional interstitials are preferentially deposited near these vacancies. Using an estimated energy stored in each Frenkel pair of 6 eV the resistivity increment at 5 K of unit concentration of Frenkel defects in platinum is 12×${10}^{-4\mathrm{}}$ Ωcm.