FORCE MICROSCOPY STUDIES OF LANGMUIR-BLODGETT-FILM OF ETRAMETHYL-4,5-DIHYDRO-1H-IMIDAZOLYL-1-OXY-3-OXIDE

The organic compound etramethyl-4,5-dihydro-1H-imidazolyl-1-oxy-3-oxid e (1) was synthesized, and its chloroform solution was spread onto dou ble-distilled water. The 10-layered Z-type Langmuir-Blodgett (LB) film s were transferred successfully to a slide substrate at a constant pre ssure of 25 mN/m with a suitable dipping speed. The topographic and th e frictional properties of the LB films thus formed were studied with an atomic force microscope (AFM) and a lateral force microscope (LFM) in the contact mode in air at ambient temperature. Furthermore, the LB films were imaged with the AFM in the tapping mode and with the magne tic force microscope (MFM) in the noncontact mode. The MFM images reve al that the LB films form quasi-one-dimensional structures composed of magnetic domains on a large scale up to 30 x 30 mu m(2). The results demonstrate not only a promising method to detect weak magnetic signal s originated from as thin as 10 molecular layers but also a spatially resolved arrangement of magnetic domains of the LB films. The MFM imag es obtained in this study furnish convincing evidence of the existence of magnetic properties in a thin organic LB film.