摘要
用改进的水解法制备了大小均匀、形状规则的球状α-Fe_2O_3超微粒;分别测量了两种不同粒度超微粒的红外透射谱;观测到了球状α-Fe_2O_3超微粒的全部表面模;讨论了微粒的聚集对吸收的影响;并用柱状微晶来近似链状聚集解释了光谱中的两个展宽吸收带;介绍了将多原子立方结构超微粒的表面模理论推广应用到单轴晶体结构的α-Fe_2O_3超微粒的情况。对表面模吸收频率进行了计算,理论数据同实验结果符合较好,并证实了推广的修正LST关系的存在。
The small spherical α-Fe_2O_3 particles with uniform size and regular shape were prepared by improved hydrolysis method. The infrared transmisson spectra of this two kinds of particles different in dimension were measured, and all surface modes of small spherical α-Fe_2O_3 particles were obtained. The effect of aggregation on absorption were discussed, and the two absorption bands in spectra were explained with the approximation of chain aggregation by cylindrical microcrystals. Surface mode theory of multi-atomic cubic particles was generalized and applied to α-Fe2O_3 particles in monoaxial crystal structure. The theoretical results of surface mode frequency of α-Fe2O_3 particles were presented, which agreed well with those of experiments. The existence of generalized modified LST relation was verified.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
1989年第10期1585-1592,共8页
Acta Physica Sinica
基金
国家教育委员会博士点基金
