Cr^(3+)∶LiSrAlF_6晶体的太赫兹-红外光谱研究

Study on Terahertz-Infrared Spectra of Cr^(3+)∶LiSrAlF_6 Crystal

实验测量了室温下掺铬氟铝酸锶锂(Cr3+∶LiSrAlF6,LSAF)晶体0.1~3 THz的时域光谱,以及50~4000 cm-1范围内的红外光谱。结果分析表明:在0.2~1.5 THz波段LSAF晶体的吸收系数小于30 cm-1,折射率在0.5~1.5之间变化。红外波段内从30~1238 cm-1为声子吸收带,透射率几乎为零。最高的纵光学模声子的频率大约是1238cm-1,由此求出这支声子的Al-F键的力常数为5.0288 N·cm-1。

THz time domain spectrum of Cr3 ＋∶ LiSrAlF6crystal in the range from 0.1 to 3 THz and the infrared spectrum in the range from 50 to 4000 cm-1were measured at the room temperature and discussed.In the range from 0.2 to 1.5 THz,the absorption coefficient is less than 30 cm-1and the values of the refractive index are 0.5 to 1.5.There is a band of the phonon absorption from 30 to 1238cm-1in the infrared spectrum,the transmittance is very little and nearly zero.The highest frequency of the longitudinal optical phonon model is about 1238 cm-1,and the force constant of Al-F ionic chemical bond from the highest frequency was calculated to be 5.0288 N·cm-1.