  We report here a linear fluoride-bridged Double-Decker Dysprosium
metallacrown with high-performance SMM. The successful introduction of stronger
magnetic exchange-coupling in the axial direction, which is collinear with the
Ising-type magnetic anisotropy axis of dysprosium ions, plays a pivotal role in
improving the SMM properties of the double-decker Dysprosium metallacrown.
