e etals Mesoporous materials low-K dielectrics Zeolites Silica gels Porous glasses 1UU▣ 0ns Lifatime ins) 142ns 各种材料的正电子寿命
Positron Lifetime 300 ●GG4 e 280 OLDA CdTe 260 (sd)oeyl 240 Ge InP GaAs o 220 200 180 80 200 220 240 260 280 300 Experiment (ps) Positron lifetimes for some semiconductors.The solid and open circles give the Generalized Gradient Approximation LNSP GGA)and the Local-Density Approximation (LDA) results as a function of the experimental ones,respectively
–±·¨Æ±² ¥·ºª¨·³ª º±Æ ±³ª ª³·½±²º´½¨±ÆÚ Ã¸ª ±¥·º ø²º ±°ª² ½·Æ½¥ª ¹·™ª ¨¸ª Ÿª²ªÆø¥·¶ªº ŸÆøº·ª²¨ fl°°Æ±®·³ø¨·±² ¯ŸŸfl˜ ø²º ¨¸ª ‘±½ø¥Û‹ª²·¨ß fl°°Æ±®·³ø¨·±² ¯‘‹fl˜ ƪ´¥¨ ø ø º´²½¨·±² ±º ¨¸ª ª®°ªÆ·³ª²¨ø¥ ±²ªÙ ƪ°ª½¨·™ª¥ßÚ
SCA 22Na Source 1.27 MeV Y Start PM Start MCA 1.27 MeV Sample e TAC N 60 Stop Y←Y stop PM 511 kev 511 kev SCA Scintillator 511 keV 2 LNSP
BaF2 HW 面目 图 D DE LNSP
℃1=169.0ps 实测的正电子寿命谱 10000 口 T T 口 MELT拟合结果 T2=382 1000 。 00 ℃2=375.6ps 吕 0.25 0.20 100 5000 015 T1=164.5p5 T3=2258.1ps 0.10 0.05 0.00 100 1000 Litetime,ps