Seifert, UdoWagner, Herbert2011-12-232016-03-312011-12-232016-03-311989364884754http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-69544http://elib.uni-stuttgart.de/handle/11682/7834http://dx.doi.org/10.18419/opus-7817Activated processes at surfaces such as desorption or sublimation may exhibit a thermal anomaly at the Curie point of a magnetic substrate. We propose to measure this anomaly with an applied magnetic field H, and we predict a decrease in the reaction rate proportional to Hx with x(T > Tc)=2, x(T < Tc)=1, and x(T = Tc)=2/δ1, where δ1≃1.9 is an exponent for ordinary phase transitions. In the case of a surface transition, or if the substrate is a film with two-dimensional Ising behavior, the anomaly is significantly enhanced.eninfo:eu-repo/semantics/openAccessMagnetokatalytischer Effekt , Hedvall-Effekt , Oberfläche530Critical magnetic field dependence of thermally activated surface processesarticle2011-12-23