It is well established that single crystals of B2-structured Fe-Al change from paramagnetic to ferromagnetic upon plastic deformation. This strain-induced ferromagnetism arises mostly from Fe atoms which have three or more like nearest neighbours in antiphase-boundary tubes. Such Fe atoms carry magnetic moments according to their local environment. In this study, the saturation magnetizations, M S , of cold-rolled Fe-34 at.% Al, Fe-40 at.% Al and Fe-43 at.% Al single crystals were measured in a vibrating-sample magnetometer from 77 K to (...) room temperature and transmission electron microscopy was used to confirm the presence of APB tubes. After magnetic measurements, rolled single crystals were heated in a differential scanning calorimeter at 20 K min m 1 to 973 K and the enthalpy associated with the removal of the APB tubes measured. From the enthalpy measurement, the APB tube density and the number of Fe NNs were estimated. Hence, the M S values at 0 K were calculated. These were in good agreement with the experimentally determined values. (shrink)

The two available mechanisms for antiphase-boundary tube formation under single-slip conditions are compared. Some of the assumptions involved such as the driving force for limited fast climb at jogs and the conditions for the transformation of Kear-Wilsdorf locks into dipoles are re-examined. Various implications of the two mechanisms are analysed and they are also compared with experimental observations in L1 2 alloys. It is shown that the trailing of APB tubes by climb-relaxed jogs offers explanations of current microstructural features that (...) are often less constraining than the bypassing of Kear-Wilsdorf locks and subsequent dipolar cross-slip annihilation. Evidence is also provided in support of the generation of APB tubes by direct cross-slip annihilation confirming a manoeuvre originally proposed for B2 alloys. (shrink)