Magnetic moment and pinning of Abrikosov fluxoids in a Al--13.5 at.% Ag alloy

The pinning force of Abrikosov fluxiods was investigated in samples of the supersaturated solid solution Al--13.5 at.% Ag with different defect structures obtained by thermal ageing and ranging from isolated lamellas of the γ' phase in the matrix to a systematic lamellar structure. The pinning force was determined by two independent methods: mechanically (from the maximum critical angle of sample rotation) and from the magnetic moment. It was found that the pinning force and the hysteresis of the magnetization curve both increase with the precipitation of the solid solution. The values of the pinning forces obtained by both methods were in quantitative agreement within the limits of experimental error. A possible explanation of the results obtained is put forward