Enhancement of Optical Faraday Effect of Nonanuclear Tb(III) Complexes

The effective magneto–optical
properties of novel nonanuclear
Tb­(III) complexes with Tb–O lattice (specifically, [Tb9(sal-R)16(μ-OH)10]+NO3–, where sal-R = alkyl salicylate
(R = −CH3 (Me), −C2H5 (Et), −C3H7 (Pr), or −C4H9 (Bu)) are reported. The geometrical structures
of these nonanuclear Tb­(III) complexes were characterized using X-ray
single-crystal analysis and shape-measure calculation. Optical Faraday
rotation was observed in nonanuclear Tb­(III) complexes in the visible
region. The Verdet constant per Tb­(III) ion of the Tb9(sal-Me)
complex is 150 times larger than that of general Tb­(III) oxide glass.
To understand their large Faraday rotation, electron paramagnetic
resonance measurements of Gd­(III) complexes were carried out. In this
Report, the magneto–optical relation to the coordination geometry
of Tb ions is discussed.