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Zener Polarons (ZP) and Zener Polaron ordering (ZPO)  is the main result of Daoud-Aladine PHD thesis at the LLB french neutron source (1998-dec 2001) directed by Juan Rodriguez-Carvajal (now at the ILL european neutron source)  revisiting the Ground State of ONE Prototype half-doped Manganese Perovskites. ZPO original published SDN work can be only performed thanks the high flux of the ILL AND the UNIQUE experise of  Juan Rodriguez-Carvajal teached to Daoud-Aladine, in the quantitative data treatement of TWINNED single crystals that is providing accurate TWIN FRACTIONS: there is simply no equivalent, in the whole manganites litterature.

Its unicity has never been really recognised, and it is still to date UNJUSTLY considered as a CONTROVERSIAL structural model for the charge ordered superstructure proposing a P 21 n m symetry challenging the P 21/m symmetry of the accepted one (the "Radaelli" structure), Radaelli's most cited work as first author (1079 citations in Oct 2021!) : excepted Transmission electron Microscopy studies of one Group, the WHOLE scientific comunity  refused to consider the superiority of  single crystal work in this area.

This Single Crystal Neutron Diffraction (SND) study of Zener Polaron ordering (ZPO), is a paper published after formal appeal to the Phys. Rev. Lett editors beacause it is audaciously disputing the celebrated Goodenough Model (GM) of La0.5Ca0.5MnO3, the interpretation made in the 50's assuming ionic Mn3+Mn4+ ordering in doped manganites of their CE-type magnetic structure determined using neutron powder diffrection (NPD)  : arguably, a main concern for the SND work, is that the new symmetry interpreted as a ZPO was obtained in a nearly half-doped material (PCMO i.e Pr1-xCaxMnO3, with x=0.4 instead of x=1/2): between 2002-2004, working as a post doc at the Laboratory for neutron Scattering PSI, Switzerland, this lead A. Daoud-Aladine to advertised in lab seminars and talks worldwide cumlminating in an American tour of Los Alamos (invitged by M. Jaime), Argone (invitged by S. Rozenkrantz), NIST (invited by J. Lynn!) Neutron faciities organised around an....


presenting everywhere one of the KEY idea : the Goodenough Model adapted exchange model to the ZPO proposal. It raised in particular the interest of Daniel Khomski, who got inspired by the non-colinear magnetic order I was proposing, and the non-centrosymetry of the experimental structure I determind. Khomski et al used a DDEX version of our proposal (called Bond centered CO - BC-CO having an "orthogonal" magnetic phase) assumed at x=0.4 and a DDEX version of the Goodenough model (the site centered SC-CO that assumes CE-type order) assumed at x=0.5 and suggested that their mixture in "intermediate" phases (0.4<x<0.5) is multiferoic, thus, defining a concept of Multiferroicity induced by charge ordering, which induced very fruitful reasearches, especially in the PCMO system.

However, one assumption made by Khomskii et al DDEX theory of PCMO is certainly phenomenologically wrong : PCMO40 has a so called pseudo-CE magnetic order, not an orthogonal order, and  in my unpublished talks, I showed my other PhD results (neutron powder diffraction) and pictures later made during py post doc defining a heuristic "a Goodenough approach adapted to ZPO" wich provide detailed description of the change from CE-type (x=0.5) to pseudo-CE type order in the  0.3<x<0.5 PCMO CO/CMR not only inspired by the available ionic models but improving them I claim .  And the only thing I need to assume to do all that, is that the ZPO symetry is also valid at x=0.5.

But... That was deemed CONTROVERSIAL... and in all this 1st 7 YEARS studies of ZPO in half-doped manganites with CE-type magnetic order, this was also unfairly hiddering how much to start with... making a half-doped manganite single crystal for Neutron Scattering is extremely difficult...