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

• Published in: Materials Science & Engineering C 1999-12, Vol.8, p.299-308
• Main Authors: Khomutov, G.B, Koksharov, Yu.A, Radchenko, I.L, Soldatov, E.S, Trifonov, A.S, Tishin, A.M, Bohr, J
• Format: Article
• Language: English
• Subjects: Langmuir–Blodgett films; Magnetic properties; Rare-earth cations; STM
• ISSN: 0928-4931; 1873-0191
• DOI: 10.1016/S0928-4931(99)00025-9

We describe the preparation and characterization of rare-earth-containing stearic acid Langmuir–Blodgett (LB) films. Stearic acid monolayer behavior on the rare-earth-containing aqueous subphase has been analyzed by thermodynamic measurements. The monolayer compression isotherm shape changed substantially by varying the anion type at the constant rare-earth cation content and pH in aqueous subphase. The conditions necessary to form highly integrated mono- and multilayered rare-earth-containing LB films were investigated. The deposited mono- and multilayer gadolinium (Gd)-containing LB films were 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 about 500 K, significantly higher than Curie temperature in bulk metal Gd. Low-field hysteresis of microwave absorption was observed in these films and pointed out to the existence of remanence magnetism in created material.