• [1]

    Wang Shuying et al，J. Phyr. C: Corzderzr. Mauer, Vl(1989), Supplement B.[2] M. Eldrup, Positron Solid State Physics, Editric Compositor-Bologno, 1983, p. 644[3] W. Brandt, et al., Phys. Rev., 142(1966), 231.[4] I. D. McGervy, et al., Phys. Rev., B2(1970), 2421.[5] J. R. Stevens, et al., Phys. Rev. Lezzerr, 29(1972), 166,[6] W. Brandt, et al., Phys. Rev，B12(1875), 2579.[7] S. J. Tao, Appl. Phys., 10(1976), 67.[8] P. Kindl, et al., Phys. Stat. Sol., (a)58(1980), 489.[9] D. P. Kecr, Can. J. Phys., 52(1974), 935.[10] J. H. Hadley, et al., Chem.Phyr. Letterr, 12(1971), 291.[11] C. Dauwe, Positron Annihilation, North Holand Publ. Comp., 1982, p. 663.[12] P. Kindl, et al., Phys. Stat. Sol., (a)81(1984), 293.[13] P. Kindl, et al., ibid., (a)104(1987), 707.[14] S. J. Tao, et al., Proc. Phys. Soc., 85(1965), 463.[15] Zhang Tianbao, Phys. Rev. Letters, A126(1987), 189.[16] 张天保，第四次中国电子学会学会文集(1987 ).[17] Tianbao Zhang, et al., Nucl. Ints. Methods, A256(1987), 398[18] A. Bertollacini, et al，J. Phys, C7(1974), 3827.[19] 王淑英，高能物理与核物理，7(1983)，408,[20] P. Kirkegaard, et al., Comp. Phys. Commun., 7(1974),401.[21] P. KirKegaard, et al，ibid., 23(1981), 391.Dauwe, C., Positron Annihilation, North Holand Publ.Camp., 1982, p. 663.