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Iron-based Fe–Mn–Al–Ni shape-memory alloys are of rather low materials cost and show remarkable pseudoelastic properties. To further understand the martensitic transformation giving rise to the pseudoelastic properties, different Fe–Mn–Al–Ni alloys have been heat treated at 1473 K and quenched in ice water. The martensite, which is formed from a body-centred cubic austenite, is commonly described as face-centered cubic (f.c.c.), even though there are also more complex, polytypical descriptions of martensite. The presently studied backscatter Kikuchi diffraction (BKD) patterns have been evaluated, showing a structure more complex than simple f.c.c. This structure can be described by nanoscale twins, diffracting simultaneously in the exciting volume. The twinned structure shows a tetragonal distortion, not uncommon for martensite in spite of the lack of interstitial elements. These features are evaluated by comparing the measured BKD patterns with dynamically simulated ones.

The determination of longitudinal and transverse effective masses of electrons at the point X in the x-space in AlAs is an actual problem.Recently, we have reported on Faraday rotation study in n-type AlAs (1). The present note reports on further investigations of Faraday rotation due to free carriers in two AlAs samples, in order to determine the Faraday effective mass m* F'We have measured the room temperature rotation in the spectral range 1 pm I f a S 1 0 p m with a magnetic field B = 1.63 T. The material properties and the experimental results a r e very like those described in the earlier paper (1).For the interpretation we have used the rotation angles 8 in the spectral range 2 -A and Hall coefficients measured at room temperature on the with ' free car. same samples. The theoretical connection between the longitudinal mass m the transverse II ' mass m coefficient R, and the electron concentration N is given by the following equations the Faraday effect mass m; , the Verdet coefficient 8/Bd, the Hall I' (2, 3): 2 (2) e3 h2 -e2 n2 2 (K + 2) 2 . m2 (2K t 1) 2 3 = N e -1 Bd 8% c n e m * 2 -8'It2c3n co O F ( e is the permittivity of the space and c is the vacuum velocitg of light). In 2 equation (1) the scattering time factor was set

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