【摘要】 研究了LiKSO₄中⁷Li的核磁共振谱与温度及晶体取向的关系。证实了在T_c=195K存在一个结构相变,并由实验数据推导出在这一温度以下,晶体的对称性低于P31c,每单胞至少含有六个分子式。没有证据说明有一个无公约相存在。测得181K的四极耦合常数为38.9kHz,不对称因子η=0.46,电场梯度主轴方向z与原c轴成11.6°角。更多还原

【Abstract】 The dependence of 7Li NMR spectrum in LiKO4 on temperature and crystal orientation has been studied. It is confirmed that there is a structural phase transition at Tc = 195K below which the crystal symmetry is lower than P31c and its unit cell contains at least six molecular formulae. There is no evidence of the existence of an incommensurate phase. At 181K the quadrupole coupling conatant is 38.9 kHz, the asymmetry parameter η = 0.46, and the principal direction z of the electric field gradient makes an angle of 11.6° with the original c axis.更多还原