Magnetic scattering and unusual behavior of the critical fields and other parameters: Application to borocarbides

The pair-breaking effect and its impact on the properties of borocarbides is studied. The pair-breaking effect caused by localized magnetic moments drastically affects the superconducting properties. Interaction between the magnetic moments and the resulting ordering trend lead to a behavior entirely different from the conventional picture. The main focus is on the behavior of the upper (Hc2) and lower (Hc1) critical fields. In addition, the temperature dependence of several quantities (penetration depth, coherence length, etc.) has been calculated. The theory has been applied to the borocarbide LuNi2B2C and is in very good agreement with the recent experimental data