Optical absorption and reflectivity study of the layered MnPSe 3 seleniophosphate
Optical absorption and reflectivity study of the layered MnPSe 3 seleniophosphate
复制标题
层状MnPSe 3 硒磷酸盐的光吸收和反射率研究
DOI：
10.1364/josab.16.000132
复制
发表时间：
1999
影响因子：
1.9
通讯作者：
L. Silipigni
中科院分区：
文献类型：
--
作者：
V. Grasso;L. Silipigni
分析了MnPSe_3硒磷酸盐晶体在1.0 ~ 5.5eV范围内的室温吸收和反射光谱。在这两类数据之间发现了一般的一致性。从吸收数据推导出该化合物的光学能隙为2.27 eV，与文献一致。在基本吸收边以下还观察到一个弱而宽的吸收带。的反射率光谱表现出五种结构，其中两个位于基本吸收阈值以下，而其他的位于较高的能量。光谱已被发现是类似于那些报道的相应的MnPS 3硫代磷酸盐，与所有的结构以外的吸收边移向较低的能量。对于光子能量大于吸收边的MnPSe 3的反射率光谱也显示出类似的镉和汞硒磷酸盐。考虑到这种相似性，所观察到的结构已被解释在所谓的过渡金属弱相互作用模型和弱晶体场理论。一个简化的能带图，其中的电子跃迁是负责所指出的吸收和反射率的功能，清楚地表明，绘制。
Room-temperature absorption and reflectivity spectra of MnPSe3 seleniophosphate crystals have been analyzed from 1.0 to 5.5 eV. A general consistency has been found between the two types of data. From the absorption data an optical energy gap of 2.27 eV was deduced for this compound, in agreement with the literature. A weak and broad absorption band below the fundamental absorption edge was also observed. The reflectivity spectrum exhibits five structures, of which two are located below the fundamental absorption threshold, whereas the others are positioned at higher energies. Spectra have been found to be similar to those reported for the corresponding MnPS3 thiophosphate, with all the structures beyond the absorption edge shifted toward lower energies. For photon energies greater than absorption edge the MnPSe3 reflectivity spectrum also shows a similarity to those obtained for the cadmium and mercury seleniophosphates. With this resemblance taken into account, the observed structures have been interpreted in terms of both the so-called transition-metal weakly interacting model and the weak-crystal-field theory. A simplified energy-band diagram, in which the electronic transitions that are responsible for the noted absorption and reflectivity features are clearly indicated, is drawn.