[1]舒启清,柳文军,Bhagat S M,等.多晶 La0.49Sr0.51MnO3 中的铁磁反共振[J].深圳大学学报理工版,2006,23(4):314-319.
 SHU Q i-qing,LIUWen-jun,et al.Ferromagnetic antiresonance in polycrystalline La0.49 Sr0.51MnO3[J].Journal of Shenzhen University Science and Engineering,2006,23(4):314-319.
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多晶 La0.49Sr0.51MnO3 中的铁磁反共振()
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《深圳大学学报理工版》[ISSN:1000-2618/CN:44-1401/N]

卷:
第23卷
期数:
2006年4期
页码:
314-319
栏目:
土木建筑工程
出版日期:
2006-10-30

文章信息/Info

Title:
Ferromagnetic antiresonance in polycrystalline La0.49 Sr0.51MnO3
文章编号:
1000-2618(2006)04-0314-06
作者:
舒启清12柳文军12Bhagat S M3Lofland S E3Troyanchuk I O4
1)深圳大学材料学院,深圳518060
2)深圳市特种功能材料重点实验室,深圳518060
3)马里兰大学物理系,柯里奇帕克,马里兰20742-4111,美国
4)白俄罗斯科学院固体物理研究所,明斯克220072,白俄罗斯
Author(s):
SHU Q i-qing1 2 LIUWen-jun1 2 Bhagat SM3 Lofladn S E3 and Troyanchuk IO4
1) College of Materials Science and Engineering Shenzhen University Shenzhen 518060 P. R. China
2) Shenzhen Key Laboratory of Special Functional Materials,Shenzhen 518060P. R. China
3) Department of Physics University of Mary land College Park Mary land 20742-4111U. S. A.
4) Institute of Solid State Physics National Academy of Sciences of Belarus P. Brovki Stree t 17 M insk 220072 Belarus
关键词:
多晶 La0.49Sr0.51MnO3 微波吸收铁磁反共振标度律密切合物
Keywords:
Polycry stalline La0. 49 Sr0. 51MnO3 microwave absorption ferromagnetic antiresonance scaling law intimate mixture
分类号:
O 513
文献标志码:
A
摘要:
采用谐振腔微扰技术测量了多晶 La0.49Sr0.51MnO3 的微波吸收( P MA ),观察到在居里温度 TC 或奈尔温度 TN 附近发生 P MA 呈现极小值即铁磁反共振( FMAR )现象 . 基于朗道 - 利弗希茨 - 吉尔伯特模型,磁化强度μ 0 M 对温度的依赖关系可以从 FMAR 得到 . 发现当外加直流磁场μ 0 H =0 时,不同微波频率下得到的磁化强度μ 0 M 对温度的依赖关系与标度律符合 . 然而,当μ 0 H 0 μ 0 H 120mT 时,不同μ 0 H 下得到的磁化强度μ 0 M 对温度的依赖关系与标度律不符合 . μ 0 H 平行最大微波磁场 hrf 时,在 TC 附近随μ 0 H 增加发生 FMAR P MA 值增加,且随μ 0 H 增加发生 FMAR 的温度下降,但此时在 TN 附近未观测到 FMAR. μ 0 H 垂直 hrf 时在 TC 附近随μ 0 H 增加 FMAR P MA 值减小,且随μ 0 H 增加发生 FMAR 的温度很少变化,但此时在 TN 附近发生 FMAR P MA 值和温度均几乎不随μ 0 H 变化这些结果可归因为:①多晶 La0.49Sr0.51MnO3 是一种由铁磁( FM )和反铁磁( AFM )等多态微区组成的密切合物,是一个包括多个状态和取向互不相同的畴壁的复杂系统;②在μ 0 H 增强或温度下降的过程中,都存在导致 P MA 增加或减少的两种机制的竞争 .
Abstract:
The microwave absorption (PMA ) of the polycrystalline La0. 49S r0.51MnO3 was measured by using a cavity perturbation technique, and the ferromagnetic antiresonance (FMAR) phenomenon near TC (Curie temperature) or TN (Néel temperature), i.e., the minimum of PMA , was observed. Through applying Landau-Lifschitz-Gilbert equation to monodomain ferromagnet, the temperature dependence of magnetization μ0M w as derived from FMAR. It is found that as the applied field μ0H =0, the temperature dependence o f μ0M obtained under the different microwave frequencies is in agreement with Scaling Law. However, as μ0H 0 and μ0H <120mT, the temperature dependence of μ0M obtained under the different μ0H is not in agreement with Scaling Law. In the case of μ0H parallel to the maximal microwave magnetic field hrf , as μ0H increases, the PMA values for FMAR increase at near TC and the temperatures for FMAR decrease. Meanwhile, the re is no FMAR at near TN. In contrast, in the case of μ0H perpendicular to hrf, as μ0H increases, the PM A values for FMAR decrease a t near TC and the temperatures for FMAR decrease slightly. At near TN both PMA values and the temperatures for FMAR do not change with μ0H. These results might be attributed to:the polycrystalline La0. 49S r0.51MnO3 is an intimate mixture of ferromagnetic, antiferromagnetic and charge-ordering microregions and a complex system with many domain boundaries different from each other in the states and orientations;when the field μ0H increases or the temperature decreases, there always exists a competition between two mechanisms which lead to the increase and the decrease in PMA , respectively.
更新日期/Last Update: 2015-06-26