23 July 1993
Vol 261, Issue 5120

About The Cover

Structure of a molecular-based magnet that exhibits bulk magnetization at temperatures below 22.5 K. This material contains three kinds of spin carriers, namely Mn(II) and Cu(II) ions together with radical cations, and has two, nearly perpendicular graphite-like networks that interpenetrate like the rings of a necklace. See page 447 and the Perspective on page 431. [Image: L. O. Ouahab, H. O. Stumpf, Y. Journaux]