The channeling blocking effects of ion beam in a crystal are applied as an useful tool not only in the nuclear physics but also in the solid state science in recent years In the present review, the fundamental properties of the channeling and blocking effects and the principle of the backscattering method are summerized at the first section. Then some examples of applications to the deterxmination of location of foreign atoms in a crystal lattice, measurement of lattice disorder, studies on phase transition as well as recent investigation on channeling phenomenon are introduced.
Strain behavior of organic molecular crystal under hydrostatic high pressure up to 8 kb was investigated by x-ray diffraction method at 20°C. Crystalline polymers were mainly studied. It was found that strains of polymer crystals take place predominantly in the lateral direction to the fiber-axis. Even polypropylene and polyoxymethylene, which have low Young's moduli of crystal in the fiber-axis direction due to the helical structure of chain molecule, exhibited no detectable strain in this direction under hydrostatic pressure Adamantane displays reversible phase transition from cubic to tetragonal structure at pr =4800kg/cm2, where it contracts 3.8% in one of the cubic axis but elongates 1.1% in both of the other two axis thus giving 1.4% volumetric compression. For the in terpretation of these results, an advanced theoretical (energetical) treatise in the molecular level seems to be required. The experimental results were discussed in terms of molecular conformation, equation f stote, anharmonicity, Grüneisen parameter, bulk compressibility, crystal density, packing density, etc.
AuCu alloy particles were prepared by vacuum evaporation technique and studied by means of high resolution electron microsocpy including lattice image technique. The structure of the alloy particles just after the deposition was, in general, the ordered structure, AuCu I, and the following heat treatment after the deposition was necessary to form AuCu II particles. The growth process from AuCu I to AuCu II was followed up by the observation of specimens with various durations of the heat treatment. The simultaneous evaporation technique was more favourable to grow AuCu II particles than the successive evaporation technique. With decreasing the particle size, the transformation from AuCu I to AuCu II turned to be difficult and AuCu II particles less than 80 A in diameter could not be found in the present experiment. For small AuCu II particles, the distortion of the antiphase domain boundaries at the periphery of particles was observed, besides a zigzag nature of the antiphase domain boundaries.