EPR study of some radical, radical pairs, crystal structure and structure phase transition

• Main Authors: Kuo-Tung Liu, 劉國棟
• Other Authors: Jiang-Tsu Yu
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/48801286222124598918

碩士 === 國立師範大學 === 物理研究所 === 82 === The thesis includes the following four researches: 1.Two chemically inequivallent [N(CH3)3]+ radical species produced via r-irradiation were detected by EPR in TrMCC crystal. This indicates a twofold, static disorder of the TrM ions. 2.The hexagonal P63/m to monoclinic P21/m structural phase transition in TMCC has been investigated by EPR. The result indicates the presence of merohedral twinning below the phase transition. 3.Two chemically inequivallent V4+ ions were detected by EPR in vanadium-doped KTiOPO4 crystal. The results allow one to identify the occupation sites of the doped V4+ ions and to conclude that the doped V4+ ions form VO2+ ions. 4.Irradiation of (NH4)2S2O8 single crystal with uv light produces two kinds of radical pairs, pairs I and pairs II. Radical pairs I is stable at room temperature, and can be identified to be SO5- pairs. Radical pairs II can be produced by uv-irradiation and detected by EPR only at low temperatures and identified to be SO4- pairs.