Experimental evidence for magnetic ordering in a literally two-dimensional magnet

The electron spin resonances of literally two-dimensional magnetic structures, formed of manganese stearate by the Langmuir-Blodgett technique, have been measured down to 1.3K. In one such structure the resonance field decreased abruptly at 2.0 K by more than 1000 Oe, and was highly anisotropic below this temperature. These, and other observations can be explained by the hypothesis of weak-ferromagnetic ordering. © 1978.