STUDY ON THE RESISTIVITY AND HALL EFFECT OF MgB2 AND Mg0.93Li0.07B2

Abstract

The temperature dependences of resistivity and Hall coefficient of MgB2 and Mg0.93Li0.07B2 were measured, and the temperature dependence of cot-ΘH was calculated. The result of resistivity indicates that MgB2 and Mg0.93Li0.07B2 nearly have the same transition temperature. The-possible effect on transition temperature has been discussed. The measurement of Hall coefficient suggests the type of charge carriers is hole, and the Hall coefficient of Mg0.93Li0.07B2 becomes a little smaller compared with that of MgB2 which is attributed to Li doping . Both the decrease with increasing temperature-and-the temperature dependence of cotangent of Hall angle are proportional to the square of temperature.

Semiconducting transport characteristics and their regulation in metal quantum structures

“…传统半导体材 料的载流子浓度较小, 且在高度集成的短沟道器件中 栅控能力减弱、载流子的输运损耗增大 [13] . 相较而言, 金属材料在费米面附近的态密度明显增大, 费米能级 处的电子浓度通常比半导体材料增加两个量级以 上 [14,15] , 可显著提高导电能力, 且在小尺度下具有弹道 电导效应 [16,17] , 呈现极低的能量损耗, 并且具备更好的 高频表现, 是制备短沟道器件的理想材料. 然而, 由于 本征的零带隙以及过高的电子浓度, 无法直接通过栅 极调控金属中电子输运的通断 [18] .…”