Rare-earth-containing planar magnetic materials formed using Langmuir-Blodgett technique

We describe the preparation and characterization of rare-earth-containing s tearic acid Langmuir-Blodgett (LB) films. Stearic acid monolayer behavior o n the rare-earth-containing aqueous subphase has been analyzed by thermodyn amic measurements. The monolayer compression isotherm shape changed substan tially by varying the anion type at the constant rare-earth cation content and pH in aqueous subphase. The conditions necessary to form highly integra ted mono- and multilayered rare-earth-containing LB films were investigated . The deposited mono- and multilayer gadolinium (Gd)-containing LB films we re studied by scanning tunneling microscopy (STM) and electron paramagnetic resonance (EPR) techniques. The temperature dependence of EPR signal in Gd -containing LB films indicates the magnetic ordering with a characteristic temperature of transition to complete disordered paramagnetic state of abou t 500 K, significantly higher than Curie temperature in bull; metal Gd. Low -field hysteresis of microwave absorption was observed in these films and p ointed out to the existence of remanence magnetism in created material. (C) 1999 Elsevier Science S.A. All rights reserved.