High temperature steady-state creep, TEM observation of defect structures and Hall effect in intermetallic compounds lithium-aluminum and lithium-indium

High temperature creep properties, TEM observation of defects and the effect of plastic deformation on electrical properties were studied through the determination of creep mechanism from the activation energy, power law exponent and TEM and optical microscope observations and Hall coefficient measurement of deformed and undeformed specimens.; The Burgers vector of the dominant dislocations in LiAl and LiIn was determined to be (a/2) (110) which was energetically favorable suggested by Huang and also in this dissertation. Antiphase-boundaries were also observed and determined to be of the (a/4) (111) (110) type.; Since the power law exponent was about 5 and a substructure of dislocations was observed, the rate-controlling creep mechanism was dislocation climb for both LiAl and LiIn. The creep activation energy was higher than that of Li diffusion. At high temperatures, diffusion of Al (or In) atoms and thermally produced vacancies may be controlling the creep mechanism. Furthermore at high temperature and small stress, grain-boundary sliding occurred in both compounds. High exponent of power law obtained for the Li-deficient LiIn specimens at intermediate temperature range suggested the pipe diffusion mechanism.; The results of room temperature Hall coefficient measurement were not so accurate due to low intensity of magnetic field. It was, however, proposed that the dislocations in LiAl and LiIn may be charged. The experimental data varied with specimen but the tendency obtained in the present measurements was that dislocations in LiAl and LiIn probably acted as donors for the Li-deficient compositions, while they acted as acceptors for the Li-rich compositions. The results of Hall coefficient measurement of an undeformed and some deformed specimens of Li{dollar}sb{lcub}50{rcub}{dollar}Al{dollar}sb{lcub}50{rcub}{dollar} suggested that the majority carriers changed from holes to electrons due to plastic deformation. Future experiment on the Hall effect with high magnetic field and wider temperature range is required to support the present proposal.