“…Experimentally it is characterized by a variety of techniques, including X-ray diffraction (Bartels, 1983;Bartels & Nijman, 1978;Bassignana & Tan, 1989;Bensoussan, Malgrange & Sauvage-Simkin, 1987;Chu, Macrander, Strege & Johnston, 1985;Fewster, 1982;Hornstra & Bartels, 1978;Ishida, Matsui, Kamejima & Sakuma, 1975;Matsui, Onabe, Kamejima & Hayashi, 1979;Olsen, Nuese & Smith, 1978;Olsen & Smith, 1975), transmission electron microscopy (Cherns, Kelly & Preston, 1988), backscattering spectrometry with ion channeling (Hamdi, Speriosu, Tandon & Nicolet, 1985) and by other spectrometric techniques (Lee & Laidig, 1984). The most accurate results are given by the X-ray techniques, mainly double-and triple-crystal diffractometry.…”