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All in all, by making this study and the PhD of G. Johnstone totally hidden and never ever comunicated to me, the grant  and the PhD was constituting an unfair distribution of resources, which was building a severe CONFLICT OF INTEREST WITHIN THE ILL Diffraction program masking the refusal by Toby Perring to establish important discussion in a Subject that I have originally defined, whilst enabling Toby Perring to be dually involved as a SPY in my ILL crystallography work on PCMO where he had been an long term collaborator/co-propser: these ILL structural studies of PCMO50 made UNOFFICIAL by Perring, where becoming less and less ambiguous, in contrary to the OFFICIAL advertisement made in the ISIS anual report shown above.

Politically, This ISIS-INS studies of PCSMO, constitute the MAIN OUTCOME of this grant, meant to develop INS-TOF metodologies. Toby Perring is not implied though he would become a key "ELUSIVE" actor of the ISIS-MAPS experiment (to quote the aknowledgement section of the PhD thesis), completed with EU money & motivated without ever saying it frankly, by ZPO related problematics studied with the ILL diffraction part of the funded PhD: that is explicitely mentionned in the introduction of the PCSMO study part "The two models both have identical magnetic unit cells, with the majority of the magnetic moment located in the 3d orbitals of the Mn moments. The ZP model does predict that some of the moment will be found between the two Mn moments, near the oxygen site. However, this would be small and is therefore difficult to measure, see Chapter 4" However, that presence of a magnetic moment/holes on oxygen ascribed in this quotation of the Thesis to the ZP model (which BTW cannot be adressed by the DDEX theory), is studied in the Ch 4 and compared to ab-initio studies referring ONLY to Ferrari work - but that is done boycotting again Zheng & Patterson work  supporting a similar phenomenology motivated by ZP ordering, but which get cited nowhere in this PhD. Like the INS part, all the analyses of those diffraction work in the PhD dutifully ignore the superstructure and provide analyses in the average structure.



In the case of bi-layerd PCSMO, the charge order and orbital is assumed to be the same in the "Pseudo-Goodenough model" and the "dimer model" however, the crucial question wether the ZP model can be adapted to provide an alternative structure and orbital order  of the compound is dutifully ignored.  Between zigzags, the total abscence of discussion about structural aspects  lead to arbitrarily set for the "dimer model" an interaction JA2=AF that could be predicted to be F...

...if the orbital order/MnO6 octahedral distortions charaterizing the ZP model in PCMO50, could have been proven to be adaptable to the bi-layerd compound: Having been excluded from any collaborative effort, I have not checked that carefully but I'm almost sure the ZP model can be adapted to this bi-layerd material beacause the buckling of MnO6 octahedra is in this compound similar to that of their 3D-counterpart .

Note indeed, that this is not the case in collapsed half-doped perovskite NaMn7O12, where ZPO has been proven to be impossible because the strong buckling due to rigid coordination of the Mn3+ on the A site  was proven to be incompatible with the developement of a ZP-type modulation: NaMn7O12 develop what's maybe the unique true realisation of the original Goodenough Model, which has a truely ionic Mn3+/Mn4+ CO/OO associated to a CE-type magnetic order, and you need a bandwidth lower than PCMO50 and YCMO50, to recover it.
I am quoting this work, because it is remarkable, and also to show that I am not uncoditionally cognitively biased toward the ZPO, unlike Perring who is conceptually biased by the DDEX theory to build up a conceptually wrong narrative to deny it.

In PCSMO wihout a similar discussion about structural aspects clarifying the Mn charge/orbital state, ZPO may or may not be relevant to this compound and concluding that ZPO is ruled out in this material is as arbitrary as the "dimer" exchange model used to discard ZPO is arbitrarily set, and therefore overstated.


In this bi-layered half-doped manganites besides the overlook of structural/charge/orbital ordering aspects making the exchange models tested in INS either arbitrary,  incomplete, or irrelevant to the problematic of ZP ordering, the data analysis of the arbitrarily chosen exchange models wrongly ascribed to "Goodenough" and "ZPO", is highly disputable : it is not an analysis comparing fits of competing model to Real data, but to a "(Goodenough Model + Resolution) x deconvoluted data" justified by the extraction of a prefactor, containing up to 20% Systematic errors in Intensity as quoted from the Thesis:

The resolution-corrected dispersion, shown in Fig. 3.22, has been obtained as described above using the Goodenough model as the means to correct for the resolution.However, any model that correctly describes the dispersion in the vicinity of each cut would have been able to produce the same resolution-corrected dispersion from the data, though only a model that provides a reasonable description of the whole dispersion would have a constant pre-factor for the intensity, as found here for the Goodenough model, see Fig. 3.23. The dispersion is now corrected for resolution and completely independent of the preliminary model used to obtain it. The experimental  dispersion [which is not experimental anymore] can now be fitted to any model one wishes to test. The models tested in this study are described in the next section, along with the results of the fits to these models.

This approach, turns out to be not sufficient to distinguish the two model. Their distinction is made via further fiddling around and I insist, the whole game may be (structurally) irrelevant to ZPO anyway... Note to be complete, the discrepancies betwen  the paper and the thesis

1.  between the Fig 3.37 of the thesis and the Fig 2 of the paper  and
2. Between The figure 1c of the paper, and how it is correcting a student error in the Fig 3.28 and Fig 3.34 : the direction of the orbital order is that of the HT charge ordered phase (Fig 3.3a of the thesis) when it should be that of LT charge ordered phase (Fig 3.3b of the thesis): as a result, the two PhD pictures are incompatible with the direction of the CE-type ferromagnetic zigzag drawn (which should be vertical according to the mistake made). The paper clarifies accordingly the exchange parametrization of the Fig 3.34 in the thesis (where JB is fitted to be the strongest and JS(trong) turns out to be the weak one...)  which tells it all about the incompetence of the PhD and/or his bosses to apply correctly the GKA rules to the two charge order present in this this system!