Investigation of the Ferroelastic Domain Structure of TMCC by Means of Nuclear Magnetic Resonance Spectroscopy

The twin domain structure of the ferroelastic P2₁/m phase of TMCC is studied by means of NMR. Six orientational domains are verified from the NMR rotational pattern at 115 K in contrast to the expected number of three for a classical 6/mF2/m transition. The rotational angle Θ between the epitaxially 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 Θ = 3.5° is in very good correspondence to the experimentally observed rotation angle Θ_exp = 4° of the EFG tensors.