YBa_2Cu_(2.88)Fe_(0.12)O_(7-δ)高温超导氧化物随温度变化的穆斯堡尔谱研究

The Study of Mossbauer Specteum of YBa_2Cu_(2.88)Fe_(0.12)O_(7-δ) High Tc Superconductive Oxide with Temperature

本文研究了YB_(a2)Cu(2.88)Fe(0.12)O_(7-8)超导氧化物在78～300K 温度区间的穆斯堡尔效应。我们发现当温度降至130K 附近时,三个晶位上的(57)~Fe 的四极裂距明显增加,且随温度降低继续增大。它们的同质异能移位则在130K 附近明显下降,在110K 附近降到最低点。我们认为导致这些变化的原因是:晶格的正交畸变明显增大,氧在Cu-O 平面排列的有序度增加。

We have studied Mossbauer spectra of YBa_2Cu_(2.88)Fe_(0.12_O_(7-8) su-perconductive oxide in temperature range 78-300K.We found that when temp-erature decreases to about 130K,the electric quadrupole splitting of ^(57)Fe atthree sublattices increase obviously and their isomer shifts decrease and reachminimum near 110K.We suggest that the reason for these is that the orthorh-ombic distortion increases and oxygen atoms in Cu-O planes get more orderlyin superconductive phases when temperature decreases to about 130K.