Li Qing'An, Gray K E, Zheng H, Claus H, Rosenkranz S, Ancona S Nyborg, Osborn R, Mitchell J F, Chen Y, Lynn J W
Chinese Academy of Sciences, Beijing, China.
Phys Rev Lett. 2007 Apr 20;98(16):167201. doi: 10.1103/PhysRevLett.98.167201. Epub 2007 Apr 19.
Contrary to conventional wisdom, our purified La 2-2x Sr 1+2x Mn2O7 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.
