CAJ | 학술논문

利用正电子湮没实验,结合理论模拟计算研究了金属间化合物MgB_2系列样品.结果表明,在不同压强下,样品的电子结构发生了变化,Mg原子层电子向B原子层方向转移,与B原子层面上的空穴载流子复合,导致费米能级降低,其附近的态密度减小,使可配对电子减少;同时由于压力作用,样品材料晶格弹性减弱,电声耦合失匹,抑制了材料的超导电性.最后对激光辐照下的MgB_2系列样品进行了分析,可能在一定光剂量范围内,有助于超导电性,过量的光子掺杂将会抑制其超导电性.
이용정전자인몰실험,결합이론모의계산연구료금속간화합물MgB_2계렬양품.결과표명,재불동압강하,양품적전자결구발생료변화,Mg원자층전자향B원자층방향전이,여B원자층면상적공혈재류자복합,도치비미능급강저,기부근적태밀도감소,사가배대전자감소;동시유우압력작용,양품재료정격탄성감약,전성우합실필,억제료재료적초도전성.최후대격광복조하적MgB_2계렬양품진행료분석,가능재일정광제량범위내,유조우초도전성,과량적광자참잡장회억제기초도전성.
In this paper,the intermetallic compound MgB_2 systems are studied by positron annihilation and theoretical calculation. The results show that,under increasing pressure,the electronic structure changes,and the electrons transfer from Mg layers to B layers. The holes in the B layers are partially filled. Density of states of MgB_2 near Fermi level decreases,hence the reduction of matching electrons. Because of the decreased flexibility of sample lattice and degree of electron-phonon coupling,the superconductivity can be inhibited. Based on the positron annihilation,we speculate that a proper dose of laser irradiation can improve the superconducting characteristics of MgB_2 samples.