光磁效应的研究

The phenomenon of variation of magnetic properties under the action of optical irradiation is known as photomagnetic effect. In this project titled "Research of photomagnetic effects", it has been studied in following aspects: 1. The mechanism of photomagnetic effect in a magnetic impueity system was advanced, and then the calculated programme of the magnetic moment and exchange constant was proposed from the s-d mixing model. The calculation shown that there exists notable photoinduced magnetic moment and the change of the exchange constant, while the energy level configuration meets the resonant-aborption condition and the ffective on-site energy of localelectrons approaches the Fermi energy. Thus, an appropriate distribution of the effective level of magnetic atoms or ions and strong electron-photon coupling are important to obtain large photomagnetic effect. 2. A scheme to calculate the effect of optical irradiation on the exchange constant was presented. The effect of pticalirradiation on the exchange constant for imperfect NiO was calculated particularly, and then the photoinduced decrease of pinning strength in NiO/FeNi bilayer was interpreted. 3. The mechanism of ferromagnetism in dilute magnetic semiconductors was studied. Above-mentioned research work indicate that in the same way as magnetooptical effect, photomagnetic effect is direct interrelated with exchange interaction and this provide a important basis for fuether studying photomagnetic effect and mproving the properties of photomagnetic materials. 4. It was reviewed to the new progresas in the study of photomagnetic effect. In addition, we have published a book 《magnetooptics》 and won a prize.

研制光磁材料，研究材料光磁效应的温度、色散特性，以及与材料成分、结构的关系。研究光磁效应的微观来源及其与磁光效应的关系，探索提高光诱导磁效应和研制高温光磁材料的途径。.预期光磁效应有较大的实用价值。利用光磁特性可望做成光存储器、光开关和光磁传感器等光磁器件，存在开发光子器件的可能性。