The Study of Spin Gap Effect of the Eu-Ba-Cu-O Sytem

碩士 === 淡江大學 === 物理學系 === 86 === Spin gap effect on bulk system of Eu/sub 1+x/Ba/sub 2-x/Cu/sub 3/ O/sub delta/(x=0~0.4) were achieved by, rather than adjusting the oxygen deficiency,alternatively substituting Eu/sub 3+/ for Ba/sub 2+/ to co...

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Bibliographic Details
Main Authors: HSIAO, POWEN, 蕭博文
Other Authors: Chien F. Z.
Format: Others
Language:zh-TW
Published: 1998
Online Access:http://ndltd.ncl.edu.tw/handle/36222637309070066850
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Summary:碩士 === 淡江大學 === 物理學系 === 86 === Spin gap effect on bulk system of Eu/sub 1+x/Ba/sub 2-x/Cu/sub 3/ O/sub delta/(x=0~0.4) were achieved by, rather than adjusting the oxygen deficiency,alternatively substituting Eu/sub 3+/ for Ba/sub 2+/ to control hole number.But thesamples were determined to be of impure phases, and the underdoping states under investigation were assumed to be of saturated oxygen concentration. In this study pure phase samples was first obtained through adjusting the molar number of Cu in the preparation process, where X-raypower diffraction analysis and EDAX were used to monitor the status of thesample. The relations between annealing time and oxygen concentration for samples of various underdoping state was found by weight measuring method, where the annealing time decreases from twenty -five days to three days as the doping concentration increases. However that spin gap temperature for most samples were determined to be above 230K was not predicted by RVB theory. This discrepancy was due possibly to the inhomogeneity of the bulk samplerevealed by magnetic measurements.