Contrary to conventional wisdom, our purified La2-2xSr1+2xMn2O7 crystals exhibit CE-type orbital and charge order as the low-temperature ground state for a hole doping level h = 0.5. For small deviations from h = 0.5, the high temperature CE phase is replaced at low temperatures by an A-type antiferromagnet without coexistence. Larger deviations result in a lack of CE order at any temperature. Thus, small inhomogeneities in cation or oxygen composition could explain why others commonly see this reentrance with coexistence.
@article{arxiv.0704.1929,
title = {Reentrant Orbital Order and the True Ground State of LaSr2Mn2O7},
author = {Qing'An Li and K. E. Gray and H. Zheng and H. Claus and S. Rosenkranz and S. Nyborg Ancona and R. Osborn and J. F. Mitchell and Y. Chen and J. W. Lynn},
journal= {arXiv preprint arXiv:0704.1929},
year = {2007}
}