研究了La0.7-xGdxSr0.3MnO3(x=0.00、0.10、0.15、0.20、0.30、0.40、0.50、0.60、0.70)体系的M-T曲线、M-H曲线和电子自旋共振谱(ESR).实验结果表明:在Gd掺杂浓度比较低时,体系表现为长程铁磁有序;当x=0.30、0.40时,体系表现为自旋团簇玻璃态;当x≥0.50以后,体系表现为反铁磁特征.对x=0.30、0.40样品,ESR谱表明在远高于Tc温度存在相分离现象.
M-T curves, M-H curves, and electron-spin-resonance spectra (ESR) of La0.7-xGdx-Sr0.3MnO3(0.0≤x≤0.70) were investigated. The experimental results indicate that the system is in a ferromagnetic long-range order at Gd low-doping level; at x=0.30 and 0.40, the samples show cluster-spin glass behavior; at x≥0.50, the system possesses the antiferromagnetic characters. For the samples x=0.30 and 0.40, ESR spectra demonstrate that the phase separation occurs at the temperature far above Tc.
参考文献
[1] | Jonker G H, Van J H Santen. Physica, 1950, 16: 337--342. [2] Wollan E O, Koehler W C. Phys. Rev., 1955, 100: 545--563. [3] Helmolt R V, Wecker J, Holzapfel B, et al. Phys. Rev. Lett., 1993, 71: 2331--2333. [4] Jin S, Tiefel T H, Mccormack M, et al Science, 1994, 264: 413--415. [5] Xiong G C, et al. Appl. Phys. Lett., 1995, 66: 1427--1429. [6] Hwang H Y, Cheong S-W, Radaelli P G, et al. Phys. Rev. Lett., 1995, 75: 914--917. [7] Fpontcuberta J, Martinez B, Seffar A, et al. Phys. Rev. Lett., 1996, 76: 1122--1125. [8] Guo Z B, Huang H, Ding W P, et al. Phys. Rev. B, 1997, 56: 10789--10792. [9] Snyder G J, Booth C H, Bridges F, et al. Phys. Rev. B, 1997, 55: 6453--6459. [10] Wang Zhi Hong, Cai Jian Wang, Shen Bao Gen, et al. Acta.Phy., 1999, 48: 757--762. [11] Bokov V A, Grigoryan N A, Bryzhina M F, et al. Phys. Stat. Sol., 1968, 28: 835--839. |
- 下载量()
- 访问量()
- 您的评分:
-
10%
-
20%
-
30%
-
40%
-
50%