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我们利用正电子湮没率对电子波函数敏感的特点研究了高T_c超导材料Y-Ba-Cu-O在相变温度附近区域的特性。正电子寿命、多普勒增宽线形参数H、S和电阻R的测量同时进行。本工作着重于利用电子密度及其动量的变化探讨高T_c超导材料相变的机制。 测量所用的寿命谱仪为标准的快-快符合系统,其分辨率为270ps;多普勒增宽仪采用液氮冷却下的高纯锗探测器测量;电阻的测量采用通常的四探针法,用镍膜为衬托的Na-22作为正电子源。样品按标准的1:2:3的配比将Y、Ba、Cu氧化物混合后烧制而成。
We use the positron annihilation rate of electronic wave function sensitive characteristics of high T_c superconducting material Y-Ba-Cu-O in the vicinity of the phase transition temperature. Positron lifetime, Doppler broadening linear parameters H, S and resistance R measurements simultaneously. This work focuses on the use of electron density and momentum changes of high T_c superconducting material phase transition mechanism. The lifetime spectrometer used for the measurement was a standard fast-fast coincidence system with a resolution of 270 ps. The Doppler broadening instrument was measured using a high purity germanium detector cooled by liquid nitrogen. The resistance was measured using the usual four-probe method , With a nickel film as a backing of Na-22 as a positron source. Samples according to the standard 1: 2: 3 ratio of Y, Ba, Cu oxide mixture after firing.