Electron paramagnetic resonance spectra of coinage metal atoms trapped in evaporated alkali-metal chloride matrices at low temperatures

Abstract

Copper, silver and gold atoms have been isolated in vapour-deposited alkali-metal chlorides in a rotating cryostat at 77 K. Their EPR spectra show much lower hyperfine interactions than gas-phase metal atoms or atoms prepared in alkali-metal chloride single crystals from metal ions in cationic substitutional sites by electron capture. The difference is thought to arise because the metal atoms in the rotating-cryostat experiments are located in asymmetric trapping sites at the interface between layers of the alkali-metal chloride, and resemble species trapped at surfaces and grain boundaries rather than those in the bulk solid.