Evidence of the Griffiths Phase in Doped Manganites Studied by Electron Paramagnetic Resonance Measurements
YUAN Song-Liu1, LIU Sheng1, CAO Heng1, SHANG Jing-Lin1, DONG Bo1, XIA Zheng-Cai1, LI Jian-Qing2
1Department of Physics, Huazhong University of Science and Technology, Wuhan 430074
2Department of Physics, Wuhan University of Technology, Wuhan 430070
Evidence of the Griffiths Phase in Doped Manganites Studied by Electron Paramagnetic Resonance Measurements
1Department of Physics, Huazhong University of Science and Technology, Wuhan 430074
2Department of Physics, Wuhan University of Technology, Wuhan 430070
Abstract： A systematic investigation of electron paramagnetic resonance above the Curie temperature Tc is performed on polycrystalline (La1-xYx)x2/3Ca1/3MnO3 (x=0, 0.15 and 0.2) samples. The results indicate anomalous paramagnetic behaviour below a temperature TG and, the anomalous extent
increases with cooling from TG. Especially, the resonance linewidth ΔHpp anomalously increases with cooling for the temperature range of TCG. The experimental observation is discussed within the framework of the Griffiths theory that predicts the existence of ferromagnetic clusters above TC. We explain the observed anomalous paramagnetic behaviour to be due to the magnetic heterogeneity caused by the ferromagnetic clusters which appear in the Griffiths phase.
YUAN Song-Liu;LIU Sheng;CAO Heng;SHANG Jing-Lin;DONG Bo;XIA Zheng-Cai;LI Jian-Qing. Evidence of the Griffiths Phase in Doped Manganites Studied by Electron Paramagnetic Resonance Measurements[J]. 中国物理快报, 2004, 21(11): 2285-2288.
YUAN Song-Liu, LIU Sheng, CAO Heng, SHANG Jing-Lin, DONG Bo, XIA Zheng-Cai, LI Jian-Qing. Evidence of the Griffiths Phase in Doped Manganites Studied by Electron Paramagnetic Resonance Measurements. Chin. Phys. Lett., 2004, 21(11): 2285-2288.
2004, Vol. 21 
