Research on the quaternary diluted magnetic semiconductor films exhibiting the large Faraday-rotation and their magneto-optical application to the high frequency magneto-optical sensors

II-VI族半导体材料CdMnTe是一种稀磁半导体，在室温下表现出顺磁特性和相当大的法拉第效应。在DMS晶格中，由于Mn~(2+)~(2+)~(2+)离子的3d电子与能带电子之间的局域磁矩之间存在自旋-自旋交换作用。这种相互作用在室温下产生了法拉第效应。由于这些特性，从其在磁光器件中的应用角度来看，CdMnTe引起了人们的极大兴趣。为了改善DM5薄膜的磁光性能，我们用分子束外延技术在透明的SiO_2石英玻璃衬底上制备了四元系DMS-CdMnCoTe薄膜，研究了薄膜的法拉第旋转角，发现薄膜中的法拉第效应得到了增强。本研究从磁光应用于t-…的角度研究了薄膜的磁光特性更多的可见区域。(1)以半导体激光器为光源，在635 nm处直接观察到了QG衬底上顺磁性MnCo：DMS厚膜的法拉第效应。(2)研究了Cd_&lt；0.43&gt；Mn_&lt；0.54&gt；Co_&lt；0.03&gt；Te薄膜的磁场线性特性，Cd_(0.40)Te薄膜在635 nm处的光吸收特性与Cd_(？)通过在更薄的衬底上制备大于5μm的厚膜和提高光学系统的透过率，有望进一步提高法拉第旋光信号的信噪比。我们将继续努力，利用我们开发的具有大法拉第旋转角的四元DMS膜来开发高频磁光传感器。较少

The II-VI semiconductor CdMnTe is known as a diluted magnetic semiconductor (DMS) that shows paramagnetic characteristics and exhibits a considerable Faraday effect at room temperature. In the DMS lattice, the presence of Mn leads to a spin-spin exchange interaction between the localized magnetic moments due to 3d electrons of the Mn^<2+> ion and the band electrons. This interaction gives rise to the Faraday effect at room temperature. Because of such characteristics, the CdMnTe has become of major interest from its application viewpoint to magneto-optical devices. In order to improve the magneto-optical property in DM5 films, we have studied the Faraday rotation in the four-element DMS CdMnCoTe films deposited on transparent SiO_2 quartz glass substrates by using molecular beam epitaxy (MBE), and showed that the Faraday effect is enhanced in those films.In this research, the magneto-optical properties of CdMnCoTe films are studied from the viewpoint of magneto-optical application in t … More he visible region. The Faraday effect in the CdMnCoTe films is compared with that of the CdMnTe film and a ferrimagnetic garnet filmThe following were performed in this research : (1)The Faraday effect in the paramagnetic MnCo : DMS thick film on QG substrate was directly observed at 635 nm using a laser diode as the light source. (2)The linear characteristics to the magnetic fields were clarified in the MnCo : DMS film.Optical absorption for Cd_<0.43>Mn_<0.54>Co_<0.03>Te film at 635 nm is identical for Cd_<0.40>Mn_<0.60>Te film, and, therefore, the figure of merit has been improved in the CdMnCoTe film by four times to the CdMnTe film. It is expected that the signal to noise ratio of the Faraday-rotation signal can be further improved by preparing thick films more than 5μm on thinner substrates and raising transmissivity of the optical system.We are going to continue with every effort in order to develop the high-frequency magneto-optical sensors using quaternary DMS films, which exhibit the large Faraday-rotation, developed by us. Less