锰-锌铁氧体的x-射线荧光光谱分析法

锰-锌铁氧体是用作计算机、电视机、通讯机等电子设备中的一种软磁材料,其磁性能与其化学成分密切相关。要制备优质锰-锌铁氧体,必须精确分析、严格控制其化学成分,传统的湿化学分析法就难于满足这种要求。在研制锰-锌铁氧体的工作中,通过近千个样品分析表明x-射线荧光“强度比”的方法,能方便地解决这一问题。此法是通过解下列方程式     

A Photovoltaic InAs Quantum-Dot Infrared Photodetector

A photovoltaic quantum dot infrared photodetector with InAs/GaAs/AIGaAs structures is reported. The detector is sensitive to normal incident light. At zero bias and 78K, a clear spectral response in the range of 2-7μm has been obtained with peaks at 3.1, 4.8 and 5.7μm. The bandgap energies of GaAs and Al0.2Ga0.8As at 78K are calculated and the energy diagram of the transitions in the Quantum-Dot Infrared Photodetector （QDIP） is given out. The photocurrent signals can be detected up to 110 K, which is state-of-the-art for photovoltaic QDIP, The photovoltaic effect in our detector is a result of the enhanced band asymmetry as we design in the structure.