It was recalled that the B-H complex could be aligned by stress, and reoriented with an activation energy of about 0.2eV. When the complex reoriented, the H atom jumped from one bond-centered site, adjacent to the B atom, to another. It was shown that the reorientation kinetics deviated from Arrhenius behavior at small jump rates (of the order of 10-6/s). This result supported the suggestion that H jumped via a thermally assisted tunnelling mechanism. It was also shown that the reorientation rate of B-D was greater than that of B-H at temperatures above 57K.

M.Stavola, Y.M.Cheng: Solid State Communications, 1995, 93[5], 431-4