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MgB2的电子-声子相互作用常数与超导转变温度的计算
Calculation About the Electrons-phonons Interactional Constant and Superconducting Transition Temperature of MgB2
【摘要】 计入短波声子的倒逆过程和电子的屏蔽效应,推导出电子-声子相互作用常数N(0)V的表达式,并利用有关的实验数据计算出N(0)V=0.309,Debye温度为798.45 K,纵向Debye温度ΘDL为1 137.3 K.以ΘDL取代BCSTc公式中的ΘD,求得Tc=38.8 K,该值与实验结果符合得很好.研究表明,对MgB2的超导有贡献的主要是纵向声子.
【Abstract】 By considering the umklapp processes of shortwave phonons and the screen effects between electrons,an expression of electrons-phonons interactional constant N(0)V is induced,and N(0)V=0.309,the Debye temperature ΘD=798.45 K and which longitudinal value ΘDL=1 137.3 K are calculated,by use of the concerned experimental data.Replacing ΘD in the BCS formula of Tc with the numerical value of ΘDL.It is obtained that the superconducting transition temperature is Tc=38.8 K,which agrees well with experiment.The results show that superconducting is dominated by the longitudinal phonons.
【Key words】 MgB2; longitudinal Debye temperature; superconducting transition temperature; electron-phonon coupling constant; screen effects; umklapp processes;
- 【文献出处】 河北师范大学学报(自然科学版) ,Journal of Hebei Normal University(Natural Science Edition) , 编辑部邮箱 ,2007年04期
- 【分类号】O511
- 【下载频次】101