EVIDENCE FOR THE SELF-INTERSTITIAL MODEL OF LIQUID AND AMORPHOUS STATES FROM LATTICE-PARAMETER MEASUREMENTS IN KRYPTON

One of the most unexpected and surprising predictions of a recently pr oposed interstitialcy model for condensed matter states is that the se lf-interstitial concentration just below the melting point should be o nly an order of magnitude below the vacancy concentration. This predic tion can be tested using existing lattice parameter measurements if a suitable method of estimating the defect-free crystal expansion is fou nd. We have developed such a test and deduce an interstitial concentra tion of 7 x 10(-4) near the triple point of krypton. This value is a s triking confirmation of one of the boldest predictions of the intersti tialcy model of condensed matter states. For copper, silver, gold and aluminum, where the defect density is smaller, less certain but positi ve evidence for interstitials in thermal equilibrium is also obtained.