Study on specific heat and two energy gaps of MgB2 samples prepared by ambient pressure and high pressure
常压和高压合成MgB2的低温比热及两个超导能隙研究

Specific heat of MgB 2 prepared by ambient pressure and high pressure has been measured in temperature range from 6K to 80K.The electron contribution to the specific heat is investigated by considering Einstein mode.A large difference between Dybye temperatures obtained by ultrasonic measurement and fitting of low-temperature specific heat is interpreted.An anomaly of electronic specific heat is observed at 12K,which can be attributed to the second energy gap of MgB 2.The effect from different sample preparation methods,i.e. ambient pressure and high pressure,is primarily discussed.