Bozin E S, Schmidt M, Deconinck A J, Paglia G, Mitchell J F, Chatterji T, Radaelli P G, Proffen Th, Billinge S J L
Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824-2320, USA.
Phys Rev Lett. 2007 Mar 30;98(13):137203. doi: 10.1103/PhysRevLett.98.137203. Epub 2007 Mar 27.
The detailed evolution of the magnitude of the local Jahn-Teller (JT) distortion in La(1-x)Ca(x)MnO3 is obtained across the phase diagram for 0< or =x< or =0.5 from high-quality neutron diffraction data using the atomic pair distribution function method. A local JT distortion is observed in the insulating phase for all Ca concentrations studied. However, in contrast with earlier local structure studies, its magnitude is not constant, but decreases continuously with increasing Ca content. This observation is at odds with a simple small-polaron picture for the insulating state.
利用原子对分布函数方法，根据高质量中子衍射数据，获得了La(1-x)Ca(x)MnO3中局部 Jahn-Teller（JT）畸变大小在0≤x≤0.5相图上的详细演变情况。在所研究的所有Ca浓度下，在绝缘相中均观察到局部JT畸变。然而，与早期的局部结构研究不同，其大小并非恒定不变，而是随着Ca含量的增加而持续减小。这一观察结果与绝缘态的简单小极化子图像不符。
