Investigation of the ferroelastic domain structure of TMCC by means of nuclear magnetic resonance spectroscopy

The twin domain structure of the ferroelastic P2(1)/m phase of TMCC is stud ied by means of NMR. Six orientational domains are verified from the NMR ro tational pattern at 115 K in contrast to the expected number of three for a classical 6/mF2/m transition. The rotational angle Theta between the epita xially grown twins is calculated from the strain tensors of the three Aizu orientation states applying the algebraic approach developed by Shuvalov et al. The theoretical value Theta = 3.5 degrees is in very good corresponden ce to the experimentally observed rotation angle Theta(exp) = 4 degrees of the EFG tensors.