[en] We have prepared solid ³He crystals under constant volume conditions and characterized them by neutron diffraction and transmission. The ultimate aim of the work was the preparation of samples suitable for neutron diffraction investigations of the antiferromagnetic nuclear ordering of solid ³He below 1 mK. We describe results from different sample cells, and we have derived the relevant design parameters with respect to (a) the neutron signal and background requirements, (b) the requirements of experiments at ultra-low temperature and (c) the mechanical properties for work at high pressure. The techniques of the ³He crystal growth at pressure between 4 and 6 MPa and at low temperature are described, together with a strategy for the crystal orientation and background reduction. As a result, large ³He single crystals of good quality were obtained. With such samples, neutron experiments on magnetic order in solid ³He at ultra-low temperature shift to the experimentally feasible regime