Contents

10 June 1994
Vol 264, Issue 5165

About The Cover

View along the [111] direction of a thallium(III) oxide crystal. Blue-green spheres represent oxygen atoms and colored polyhedra represent different thallium sites. Nanometer-scale layered structures composed of this material are electrodeposited by pulsing an applied potential. Varying the potential can favor the formation of oxygen vacancies or cation interstitials. These materials have structural similarities to the high transition temperature superconductors. See page 1573. [Model: Robert Van Leeuwen and Jay A. Switzer]