Specific Heat Study of Li0.2FeTe0.6Se0.4 under Earth’s Field Cooling

• Main Authors: CHEN,TING-YU, 陳亭羽
• Other Authors: LEE,WEN-HSIN
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/03686346746957255628

碩士 === 國立中正大學 === 物理系研究所 === 104 === Li0.2FeTe0.6Se0.4 this sample when sur- magnetic field 0.5 Oe, makes ZFC (Zero Field Cooling) the magnetic gauging, Tc = 11.5 K, but cooling of in under the sur- magnetic field 0.5 Oe, the magnetic gauging (4.6 K ~ 20 K) had not seen in the entire temperature sector the obvious paramagnetic and superconductivity counter-magnetism changes the production. The specific heat may use for to discuss the block material superconductivity nature, however Li0.2FeTe0.5Se0.5 in different sur- magnetic field ZFC (Zero Field Cooling) under the gauging, discovers this superconductivity low threshold field Hc1 very small ~ 0.5 Oe, but (Field cooling) the process gauges in 0.5 Oe FC arrives the magnetization data not to change obviously, because few has the superconductor to have the so small low threshold field Hc1 characteristic, therefore we use the specific heat to gauge examine this sample once more, whether still had the superconductivity nature. Showed from our specific heat gauging result that, the Li0.2FeTe0.6Se0.4 sample under terrestrial magnetic field cooling, had not seen truly the specific heat has the superconductivity to change the phenomenon, when low temperature the general metal material specific heat mainly is by electronic and the phonon contribution, may express: C = γ T + βT3 also may write is: C/T = γ + βT2, then may figure out Li0.2FeTe0.6Se0.4 electron of specific heat coefficient γ = 36.1 mJ/mole‧K2 and phonon specific heat coefficient β = 0.73 mJ/mole‧K4 using the C/T vs T2 chart, is equal in Debye Temperature (ΘD) = 181 ± 5 K。