Inter-leg angles in tetrapod ZnO particles

Measured sets of angles of legs in 28 tetrapod ZnO particles produced by oxidizing zinc ill air have been analyzed in terms of the octahedral multiple twin (octa-twin) nucleus model proposed previously (J. Crystal Growth 134 (1993) 275; Phil. Mag. A 69 (1994) 1125), Nineteen sets of them coincide with the angle relation for the octa-twin nucleus completely relaxed by cracking along twin boundaries; the initial octa-twin nucleus is accompanied by a large elastic strain of 5%. The other sets, except two, can also be well interpreted by the growth process from some types of incompletely relaxed nucleus, where legs grow with some nucleus twins unrelaxed without forming cracks.