Crystal and magnetic structure of La_{1-x}Sr_{1+x}MnO_{4} : role of the   orbital degree of freedom
  The crystal and magnetic structure of La_{1-x}Sr_{1+x}MnO_4 (0<x<0.7) has been studied by diffraction techniques and high resolution capacitance dilatometry. There is no evidence for a structural phase transition like those found in isostructural cuprates or nickelates, but there are significant structural changes induced by the variation of temperature and doping which we attribute to a rearrangement of the orbital occupation. 
D. Senff, P. Reutler, M. Braden, O. Friedt, D. Bruns, A. Cousson, F.   Bouree, M. Merz, B. Buechner and A. Revcolevschi