Article thumbnail
Location of Repository

[[alternative]]Magnetic relaxation research in the bulk of YBa■Cu■O■

By [[author]]吳景淼, Ching Miau [[author]]Wu, 吳景淼 and Ching Miau Wu

Abstract

[[abstract]]為了了解高溫超導體的磁鬆弛機制, 我們在超導體的混合態中分別做定磁 場不同溫度及定溫度不同磁場下之磁化率對時間變化的實驗, 實驗結果以 渦流玻璃模型的解釋最為吻合。以歸一化鬆弛率R'≡M/[M×Ln(t)]分析實 驗結果,發現不論是定磁場或定溫度, 其R'都大約 成一定值, 範圍在0.02 至0.05之間, 此結果與 A.P.Malozemoff等人用渦流玻璃模型所得之0.033 相當。以渦流玻璃模型計算釘扎位能, 在同磁場(3000高斯), 溫度63 K 以下, 釘扎位能與溫度成正比, 其值從19.5K之33.2meV增加到62.5 K 之107.1 meV; 而在定溫下(19.5 K), 釘扎位能與所加磁場無關。其值 從3000高斯至 6000高斯皆約為33 meV。 In order to realize the mechanism of magnetic relaxation of high temperature superconductor, We make magnetization vs time experi- ment in mixed state of superconductor with constant temperature vs various magnetic field and constant magnetic field vs various temperature . The vortex-glass model can explain the experiment result well . We analyze the experiment result with normalized magnetization R'≡M/[M×Ln(t)] and find that R' keeps abount a constant between 0.02 to 0.05 , no matter under constant magne- tic field or constant temperature . This result approaches the number 0.033 which A. P. Malozemoff gets by vortex-glass model. We calculate the pinning pontenial by means of vortex-glass mod- el . under same magnetic field (3000 Gauss), temperature lower than 63 K , the pinning potenial is proportional to temperature. The value increases from 33.2 meV (19.5 K) to 107.1 meV (62.5 K). But under constant temperature (19.5 K) , the pinning potential has no connection with applied field . The value keeps 33 meV from 3000 Gauss to 6000 Gauss . In order to realize the mechanism of magnetic relaxation of

Topics: 磁鬆弛, 渦流玻璃模型, 釘扎位能, magnetic relaxation , vortex-glass model , pinning potential, [[classification]]38
Year: 2010
OAI identifier: oai:ir.lib.ntnu.edu.tw:309250000Q/8008
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://ir.lib.ntnu.edu.tw/ir/h... (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.